Weather - February 6

By: beell , 11:52 AM GMT on February 06, 2014

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243. WunderAlertBot (Admin)
10:56 AM GMT on March 03, 2014
beell has created a new entry.
242. beell
3:17 AM GMT on March 03, 2014
The activity with the front certainly did not pan out over SE TX. The elevated anafrontal convection over the shallow cold layer was not a surprise.

I do think you latched on to the extreme temp contrast with this system early on!
:)
Member Since: September 11, 2007 Posts: 143 Comments: 16726
241. Pcroton
2:50 AM GMT on March 03, 2014
You guys aren't the only ones who busted on storm ideas.

A difficult one for sure.



Member Since: September 26, 2011 Posts: 54 Comments: 8274
240. beell
2:09 AM GMT on March 03, 2014
I was down with your circle also-or maybe a smidge to the north. At least you're not alone!
Member Since: September 11, 2007 Posts: 143 Comments: 16726
239. 1900hurricane
2:03 AM GMT on March 03, 2014
In other news, I think my circle might have busted.

Member Since: August 2, 2006 Posts: 46 Comments: 11669
238. beell
1:59 AM GMT on March 03, 2014

03/02 18Z GFS 700 mb RH-Valid 1PM EST Thursday

A developing dry slot over the central gulf coast.
Member Since: September 11, 2007 Posts: 143 Comments: 16726
237. beell
1:41 AM GMT on March 03, 2014
Next up on the severe front should begin to come together over Florida on Thursday as an amplified mid-level trough closes off over/near the ARKLATX-leading to the development of a surface low over the central gulf coast.

The passage of a cold front across most of Florida on Tuesday will leave the northern half of the state on the edge of a cool and stable surface continental airmass. Decent return flow of un-modified gulf moisture may have to wait untill Thursday morning as the surface low begins to tighten up and the boundary begins a retreat to the north as a warm front over peninsula. The pre-existing airmass should promote a solid grungy cloud deck over the warm sector. There should be some good rainfall totals north of the retreating boundary over SC an GA later in the event

A cool and stable airmass will also exist to the west of the system over the Gulf of Mexico and the stacked and closed nature of this system should be effective in pulling the cold continental air in behind the system towards the warm sector. There may be some potential for this airmass to undercut any surface based convection along the cold-front extending out into the gulf.

As the mid-level closed low begins to tilt neutral or negative, the surface low should quickly translate to the east coast of FL under the better divergence/ascent. The shift of the surface low to the east coast will also mitigate the severe potential by limiting backed low level flow.

There still seems to be a good chance of severe thunderstorms along and south of a line from Tampa to Jacksonville on Thursday afternoon underneath a focused 60-70 knot mid level jet streak.


DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0323 AM CST SUN MAR 02 2014

...STRONG UNIDIRECTIONAL WIND PROFILES WITHIN THE WARM SECTOR MAY FOSTER ONE OR MULTIPLE SQUALL LINES CROSSING THE PENINSULA AND KEYS...WITH DAMAGING WINDS AND PERHAPS A FEW TORNADOES OF CONCERN. WHILE BUOYANCY WILL LIKELY BE LIMITED BY ONLY MODEST MID-LEVEL LAPSE RATES...THE OVERLAP OF A WARM/MOIST BOUNDARY LAYER WITH STRONG LOW-LEVEL/DEEP SPEED SHEAR COULD ENHANCE THE SVR POTENTIAL. THIS WOULD ESPECIALLY BY THE CASE IF A STRONG MID-LEVEL DRY INTRUSION COILS AROUND THE SRN SEMICIRCLE OF THE PARENT DEEP EXTRATROPICAL CYCLONE ENHANCING POTENTIAL INSTABILITY...AS SOME MODEL SOLUTIONS INDICATE...

Something to keep an eye on in the models this week. GFS shows the dry intrusion. A dry intrusion allows dry mid-level air to advect over warm and moist air in the PBL. The lapse rate is greater in the mid-levels (dry adiabatic). Given some dynamic lifting mechanism (surface convergence, vorticity advection, jet streak), the lapse rate through the entire column increases. Throw in some insolation in the cloud-free dry slot and you could end up with quite a bit more SB CAPE than currently shown in the models. It appears this may occur over the panhandle.

Member Since: September 11, 2007 Posts: 143 Comments: 16726
236. beell
12:45 AM GMT on March 03, 2014
Trying to catch up to the weather is a full-time job today.

Evening, 1900.
I'll admit, when I went to sleep last night, I didn't think I would be in a Mesoscale Discussion today!

I think the NAM knew!

That is an awesome graphic you brought here. Plussed it on Doc M;s blog when I saw it. Plussed it here also.
Thanks.

God Bless Texas!

Hello, Tf.
Your sense of humor fits right in here! As mentioned in one of the tweets associated with the lightning picture Linda dropped off, cloud-to-ground has got to be the rarest of the thundersneet. And to catch it on on film?(!)

Hiya, P.
And to think this is all on the back of isentropic upglide/slantwise convection. Well, ok...maybe a bit of a surface wave to the south. ADDED: I guess I left out the shortwave also, lol.

mPing is alive

Same story here, Linda.
Went to get something out of the truck-warm/sticky.
Went to put something back in the truck 10 minutes later-not warm/sticky!
Member Since: September 11, 2007 Posts: 143 Comments: 16726
235. Thoughtsteader
12:28 AM GMT on March 03, 2014
My, my. I believe the acronym is FROPA? I think I'll go shut my windows and doors. 6:26 p.m. ;)
Member Since: January 16, 2014 Posts: 35 Comments: 516
234. Thunderfan
11:29 PM GMT on March 02, 2014
Fog? Yep - Houston's HWO covered that the other day. :)
Member Since: April 14, 2012 Posts: 3 Comments: 801
233. Thoughtsteader
11:22 PM GMT on March 02, 2014
Oh, my goodness - you should see the fog. It looks like the front's draped right between Sugarland and Pearland,edging our way. We've not got a breath of wind now, and I can barely see across the marina, let alone the lake. Just amazing.
Member Since: January 16, 2014 Posts: 35 Comments: 516
232. Pcroton
11:01 PM GMT on March 02, 2014
This system is awesome no two ways about it.

It's absolutely exploding now.

It's been quite some time since we've had a March storm of this nature.

Member Since: September 26, 2011 Posts: 54 Comments: 8274
231. Thunderfan
11:00 PM GMT on March 02, 2014
Quoting 228. Thoughtsteader:
With or without 8 ball, Barefoot nailed this one.
My gosh, what a photo from Oklahoma. Don't know exactly where, but the credits for it are here.



Bf, I don't know whether I hope you're getting a chance to see this, or not!



Lightning just makes things better!*


*assuming you don't get hit directly or indirectly by the bolt...
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230. 1900hurricane
10:20 PM GMT on March 02, 2014
Just your run-of-the-mill 85*F state temperature differential...

Member Since: August 2, 2006 Posts: 46 Comments: 11669
229. 1900hurricane
9:55 PM GMT on March 02, 2014
I'll admit, when I went to sleep last night, I didn't think I would be in a Mesoscale Discussion today!



MESOSCALE DISCUSSION 0162
NWS STORM PREDICTION CENTER NORMAN OK
0336 PM CST SUN MAR 02 2014

AREAS AFFECTED...PORTIONS OF E AND NE TX INTO SWRN AR

CONCERNING...WINTER MIXED PRECIPITATION

VALID 022136Z - 030130Z

SUMMARY...SHOWERS AND TSTMS WILL CONTINUE TO DEVELOP OVER PORTIONS
OF EAST INTO NORTHEAST TX AND SWRN AR THIS AFTERNOON INTO THE
EVENING WITH ACTIVITY MOVING NEWD ACROSS THESE SAME AREAS.
MEANWHILE...A COLD AIR MASS IS EXPECTED TO MAINTAIN A GREATER SWD
MOVEMENT ACROSS E TX AS COMPARED TO NRN LA AS A COLD FRONT ADVANCES
SSEWD REACHING SE TX AND THE TX COAST TOWARD 00Z. LOCATIONS IN THE
WAKE OF THE COLD FRONT CAN EXPECT A CHANGE IN PRECIP-TYPE FROM RAIN
TO A MIX OF SNOW...FREEZING RAIN AND CONVECTIVELY-ENHANCED SLEET
SHOWERS. FREEZING RAIN RATES OF 0.05-0.1 INCH PER HOUR AND LOCALLY
TO 0.15 INCH PER HOUR...ESPECIALLY WITH TSTMS...ARE POSSIBLE. THESE
RATES ARE VERIFIED PER RECENT SURFACE OBSERVATIONS IN THE WRN EDGE
OF THE DISCUSSION AREA.

DISCUSSION...TRENDS IN REGIONAL RADAR IMAGERY...LIGHTNING DATA...AND
CIMSS GOES-R CLOUD TOP COOLING AND OVERSHOOTING TOP PRODUCTS
INDICATED CONVECTION AND EMBEDDED TSTMS CONTINUING TO INCREASE IN
COVERAGE AND INTENSITY SINCE 1930Z ACROSS NORTHEAST TX TO SWRN AR.
WHILE THE OVERALL HAIL THREAT HAS REMAINED LOW PER WDSS-II MESH
PRODUCT /E.G. MESH HAIL SIZE UP TO 0.5-0.8 INCH/...THE GREATER
CONCERN WITH THIS ACTIVITY WILL BE AN EXPECTED CHANGE IN PRECIP-TYPE
FROM W-E. MUCH OF THE WRN HALF OF THE DISCUSSION AREA SHOULD
EXPERIENCE THIS CHANGE TO WINTRY PRECIPITATION BY 00Z...WITH THE
SURFACE 32 F ISOTHERM EXPECTED TO EXTEND FROM INVOF TXK TO NEAR CLL
BY THAT TIME.

THE CURRENT INCREASE IN TSTM COVERAGE...WHICH IS FORECAST TO PERSIST
INTO THE EVENING...IS OCCURRING AS STRONGER FORCING FOR ASCENT
ATTENDANT TO THE UPSTREAM SHORTWAVE TROUGH CONTINUES TO SPREAD EAST
TOWARD THE ARKLATEX REGION. THIS ASCENT ATOP AN INFLUX OF
WARM/MOIST AIR ALONG A 40-45 KT SLY LLJ BEING LIFTED ISENTROPICALLY
ATOP THE COLDER POST-FRONTAL SURFACE AIR MASS WILL MAINTAIN THE
THREAT FOR TSTMS. THE EQUATOR-WARD INCREASE IN THE DEPTH OF THE
COLD AIR IN THE WAKE OF THE COLD FRONT WILL RESULT IN VERTICAL
THERMAL PROFILES TRANSITIONING TO ONES SUPPORTIVE OF MIXED WINTRY
PRECIPITATION...WITH TSTMS ENHANCING THE PRECIP RATES.

..PETERS.. 03/02/2014


ATTN...WFO...LZK...SHV...HGX...FWD...

LAT...LON 31729693 32579629 33549521 34609385 34559334 34289318
33909362 33249398 31959472 30809557 30729638 31229702
31729693
Member Since: August 2, 2006 Posts: 46 Comments: 11669
228. Thoughtsteader
8:57 PM GMT on March 02, 2014
With or without 8 ball, Barefoot nailed this one.
My gosh, what a photo from Oklahoma. Don't know exactly where, but the credits for it are here.



Bf, I don't know whether I hope you're getting a chance to see this, or not!

Member Since: January 16, 2014 Posts: 35 Comments: 516
227. beell
6:27 PM GMT on March 02, 2014
We're not too bad here, bug. Trying to make the most (blog-wise) out of a cold front!

And bf bearing news of winter.
:)

Out for a while this afternoon.
Member Since: September 11, 2007 Posts: 143 Comments: 16726
226. Barefootontherocks
3:59 PM GMT on March 02, 2014
On the sideshow this morning:
#Thundersleet
#Thundersnow

Low of 8-ball tonight
Member Since: April 29, 2006 Posts: 154 Comments: 18715
225. palmettobug53
3:44 PM GMT on March 02, 2014
Hi, beel. I was going to ask what was going on in your neck of the woods but I see I can sum it up in one word: Yikes!

Sunny and warm here today but we've got rain due Mon, Tues, Thurs and Fri. It is hard to believe we're -1.93 inches for precip for the year, with all the rain, snow and ice we've had.
Member Since: October 7, 2005 Posts: 234 Comments: 25110
224. beell
3:28 PM GMT on March 02, 2014
And it is already well underway. Some synoptic features mentioned in the MCD related to our weather.

Strong surface frontogenesis on the RAP with the cold air deep into TX already.





MESOSCALE DISCUSSION 0159
NWS STORM PREDICTION CENTER NORMAN OK
0727 AM CST SUN MAR 02 2014

AREAS AFFECTED...PORTIONS OF CNTRL/SRN/ERN OK...N-CNTRL TX...NRN AR...SRN MO

CONCERNING...WINTER MIXED PRECIPITATION

VALID 021327Z - 021930Z

SUMMARY...AN INCREASE IN THE COVERAGE AND INTENSITY OF WINTER MIXED PRECIPITATION IS ANTICIPATED ACROSS PARTS OF THE SRN PLAINS TO THE OZARK PLATEAU THIS MORNING...WITH SIMILAR ACTIVITY PERSISTING INTO THE AFTERNOON.

DISCUSSION...REGIONAL 12Z RAOBS SAMPLE A PLUME OF ELEVATED BUOYANCY ROOTED ATOP THE STRONG INVERSION OVERLYING AN ARCTIC AIR MASS THAT IS SPREADING SWD ACROSS THE REGION. INFRARED AND WATER VAPOR SATELLITE IMAGERY SUGGEST THAT THE FRINGES OF STRONGER ASCENT/MID-HIGH CLOUDS PRECEDING A SRN-STREAM IMPULSE OVER AZ/NM ARE ENCROACHING ON THIS BUOYANCY. MOSAIC RADAR IMAGERY ALREADY INDICATES THE DEVELOPMENT OF ISOLATED CONVECTION PRODUCING SLEET FROM SWRN OK TO THE OZARKS. AS THE IMPULSE CONTINUES TO APPROACH THE AREA...THE INCREASE IN ASCENT WILL ENCOURAGE THE GROWTH OF ADDITIONAL ELEVATED CONVECTION THROUGH THE MORNING...WHILE PRECIPITATION FALLOUT FROM MID/HIGH-LEVEL CLOUDS STIMULATES PRECIPITATION FROM THE LOWER STRATUS DECK /SEEDER-FEEDER MECHANISM/.

DESPITE ELEVATED WARM NOSE TEMPERATURES OF 6-12C AROUND H85 SUPPORTING COMPLETE MELTING OF HYDROMETEORS PER THE 12Z SOUNDINGS...VERY COLD TEMPERATURES IN THE SHALLOW PBL -- I.E. AOB -10C WILL LIKELY SUPPORT SLEET WITH THE CONVECTION. HOWEVER...FOR AREAS FROM NRN AR TO SERN/S-CNTRL OK AND ADJACENT N-CNTRL TX WHERE MAXIMUM TEMPERATURES BENEATH THE FRONTAL INVERSION WILL BE A LITTLE WARMER -- THOUGH STILL BELOW 0C -- FREEZING RAIN WILL BE LIKELY. LIQUID-EQUIVALENT PRECIPITATION RATES OF 0.05-0.15 INCH PER HOUR WILL BE LIKELY. THIS COULD TRANSLATE TO SLEET ACCUMULATION RATES AROUND 0.25 INCH PER HOUR...PERHAPS LOCALLY HIGHER. THE HIGHEST PRECIPITATION RATES ARE EXPECTED TO OCCUR FROM THE OZARK PLATEAU TO SERN/S-CNTRL OK AND ADJACENT N-CNTRL TX INVOF A PLUME OF 0.75-1-INCH PW PER GPS DATA.

THE OVERALL INCREASE IN COVERAGE AND INTENSITY OF SLEET/FREEZING RAIN SHOULD CONTINUE THROUGH LATE MORNING AND INTO THE AFTERNOON...WITH THE POTENTIAL FOR THUNDERSTORM ACTIVITY TO LOCALLY ENHANCE PRECIPITATION RATES.

..COHEN.. 03/02/2014

It kinda lookd this way last week.

177. beell 12:46 PM GMT on February 26, 2014
The advancing push of cool air will probably undercut any surface based storms and result in decent elevated thunder.
Member Since: September 11, 2007 Posts: 143 Comments: 16726
223. 1900hurricane
6:03 AM GMT on March 02, 2014
It's official, I've gone back in time to March/April 2013.



DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1149 PM CST SAT MAR 01 2014

VALID 021200Z - 031200Z

...THERE IS A SLGT RISK OF SVR TSTMS FOR ERN TX TO THE LOWER MS
VALLEY...

...SYNOPSIS...
SHORTWAVE TROUGH OVER THE LOWER CO VALLEY WILL EJECT EWD...REACHING
THE LOWER MS VALLEY/MID-SOUTH BY EARLY MON. ROBUST COLD FRONT OVER N
TX WILL MOVE SEWD ACROSS THE WRN GULF TO CNTRL GULF COAST...AS AN
EXPANSIVE ANTICYCLONE BUILDS OVER THE GREAT PLAINS.

...ERN TX TO LOWER MS VALLEY...
DESPITE MID-LEVEL HEIGHT FALLS/DCVA DOWNSTREAM OF THE APPROACHING
SHORTWAVE TROUGH...CYCLOGENESIS SHOULD BE NIL ALONG THE PROGRESSIVE
COLD FRONT. THIS SUGGESTS STRONG FORCING FOR ASCENT WILL PRIMARILY
REMAIN ALONG/N OF THE FRONT...YIELDING A LARGELY ANAFRONTAL
CONVECTIVE SCENARIO.
LOW-LEVEL MOISTURE RETURN BENEATH AN EML WILL
REMAIN CONFINED FROM THE WRN GULF OWING TO LOW PW VALUES OVER THE
ERN GULF. THIS SHOULD EFFECTIVELY LIMIT THE ERN EXTENT OF SURFACE
DEW POINTS AOA 60 DEG F TO THE CNTRL GULF COAST.

SCATTERED ELEVATED CONVECTION SHOULD BE ONGOING OVER PARTS OF THE
OZARK PLATEAU AT 12Z. POST-FRONTAL CONVECTION WILL INCREASE IN
COVERAGE THROUGH THE MORNING AND AFTERNOON WITH SWWD EXTENT...AS
FORCING FOR ASCENT STRENGTHENS. INITIALLY STEEP MID-LEVEL LAPSE
RATES AND STRONG SPEED SHEAR WITHIN THE CLOUD-BEARING LAYER SHOULD
FAVOR ISOLATED SEVERE HAIL.

SURFACE-BASED PARCELS ALONG THE FRONT MAY REMAIN CAPPED THROUGH PEAK
HEATING OWING TO A PRONOUNCED EML AND PERSISTENT SWLY FLOW. BY
EVENING...AN OVERSPREADING MID-LEVEL JET SHOULD YIELD SOME
SHARPENING OF THE FRONT AS IT IMPINGES ON THE PLUME OF RICHEST
LOW-LEVEL MOISTURE. INHIBITION SHOULD SUFFICIENTLY WEAKEN FOR
SURFACE-BASED STORMS FROM FAR SERN TX INTO LA. THIS CONVECTION
SHOULD GROW INTO A BROKEN BAND AMIDST 700 MB WINDS AOA 40 KT.
LOW/MID-LEVEL SHEAR WILL BE SUFFICIENT FOR SHORT-LINE SEGMENTS AND
EMBEDDED SUPERCELL STRUCTURES CAPABLE OF ISOLATED DAMAGING WINDS AND
A TORNADO. HOWEVER...GIVEN THE UNDERCUTTING NATURE OF THE FRONT
ALONG WITH LOWER MEAN MIXING RATIOS WITH ERN EXTENT...OVERALL SEVERE
RISK SHOULD BE TEMPERED IN COVERAGE/INTENSITY.


..GRAMS/ROGERS.. 03/02/2014
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222. 1900hurricane
5:33 AM GMT on March 02, 2014
Nope, not surprised at all. Still probably going out, even if it is close by. Thinking about just heading to the other side of the Brazos River in the floodplain and intercepting the cold front if there isn't anything worth chasing (and I'm not optimistic at this point, in case you haven't noticed). I did this a few times last spring and it was always pretty cool.
Member Since: August 2, 2006 Posts: 46 Comments: 11669
221. beell
4:24 AM GMT on March 02, 2014
Evening, Tf. That's sad. Better off with MOS!
MOS Guidance
MOS Guidance Product description

I'll take that good luck charm, Skye. Thanks and same to you!

ADDED: Oh, I'm guessing that is an original Skye sky.
Very interesting!

Are you really surprised, 1900?
Undercutting from the north, capping from the south.
We'll still see an active front I think.
Member Since: September 11, 2007 Posts: 143 Comments: 16726
220. 1900hurricane
4:08 AM GMT on March 02, 2014
Looks like my undercutting nightmares are about to come true. I am tired of everything remotely interesting severely underperforming and disappointing me.
Member Since: August 2, 2006 Posts: 46 Comments: 11669
219. 1900hurricane
6:56 PM GMT on March 01, 2014
My bust-o-meter is going off. Maybe I'm just being overly pessimistic...



DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1127 AM CST SAT MAR 01 2014

VALID 021200Z - 031200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF CNTRL TO EAST
TX...LA...SRN AR AND SW MS...

...SRN PLAINS/LOWER MS VALLEY...
AN UPPER-LEVEL TROUGH WILL QUICKLY PROGRESS EWD INTO THE SRN PLAINS
ON SUNDAY. AT THE SFC...A STRONG COLD FRONT WILL ADVANCE SWD ACROSS
THE SRN PLAINS AND ARKLATEX BEING POSITIONED FROM NEAR THE TX HILL
COUNTRY NEWD ACROSS EAST TX TO NEAR THE AR-LA STATE-LINE BY
AFTERNOON. WIDESPREAD ELEVATED CONVECTION SHOULD BE ONGOING NORTH OF
THE BOUNDARY FROM THE RED RIVER VALLEY NEWD INTO THE OZARKS. FURTHER
SOUTH ALONG AND JUST AHEAD OF THE BOUNDARY...THE MODELS DIFFER
CONCERNING THE TIMING OF INITIATION AND CONVECTIVE COVERAGE. THE NAM
AND WRF-NMM4 SOLUTIONS KEEP CONVECTIVE COVERAGE MINIMIZED THROUGH
LATE AFTERNOON WHILE THE GFS AND ECMWF APPEAR TO DEVELOP A LINE OR
CLUSTER OF THUNDERSTORMS ALONG THE FRONT...MOVING THIS CONVECTIVE
SYSTEM SEWD ACROSS THE SLIGHT RISK AREA EARLY SUNDAY EVENING. DUE TO
THE DIFFERENCES IN MODEL SOLUTIONS...THERE APPEARS TO BE UNCERTAINTY
CONCERNING THIS UPCOMING EVENT.

GFS FORECAST SOUNDINGS AT 00Z/MONDAY IN SOUTHEAST TX SHOW SFC
DEWPOINTS IN THE MID TO UPPER 60S F WITH LAPSE RATES FROM 700 TO 500
MB NEAR 7.5 C/KM. THIS SHOULD BE ENOUGH FOR A POCKET OF MODERATE
INSTABILITY LATE SUNDAY AFTERNOON FROM NEAR COLLEGE STATION SWD TO
THE UPPER TX COAST WHERE MUCAPE SHOULD REACH THE 1000 TO 1500 J/KG
RANGE. IN ADDITION...0-6 KM SHEAR WILL INCREASE TO 50 TO 60 KT
ACROSS SE TX AS THE UPPER-LEVEL SYSTEM APPROACHES MAKING CONDITIONS
SUPPORTIVE OF SEVERE STORMS. SUPERCELL DEVELOPMENT WILL BE POSSIBLE
DUE TO THE STRONG DEEP LAYER SHEAR BUT A QUICK TRANSITION TO A
LINEAR CONVECTIVE SYSTEM SEEMS LIKELY ALONG THE FRONT DUE TO STRONG
LOW-LEVEL CONVERGENCE. IF A LINEAR MCS CAN ORGANIZE...THEN A
SUBSTANTIAL WIND DAMAGE THREAT MAY DEVELOP SUNDAY AFTERNOON. THE
POTENTIAL FOR AN ENHANCED WIND DAMAGE THREAT APPEARS MOST LIKELY
FROM AUSTIN EXTENDING EWD INTO WRN LA AND SWD TO THE HOUSTON AREA.
HAIL WILL ALSO BE POSSIBLE WITH THE MORE INTENSE CELLS WITHIN THE
LINE. A TORNADO OR TWO CAN NOT BE RULED OUT IF CELLS CAN REMAIN
DISCRETE FOR A FEW HOURS DURING THE AFTERNOON.

AT THIS POINT...UNCERTAINTY CONCERNING SEVERE THREAT COVERAGE IS
SUBSTANTIAL. IF THE COLD FRONT MOVES SWD INTO THE SRN PLAINS FASTER
THAN FORECAST...THEN THE SEVERE THREAT AREA WOULD BE SMALLER IN
REGIONAL EXTENT. THIS COULD ALSO REDUCE TO AREAL EXTENT OF
DESTABILIZATION IN TURN REDUCING SEVERE THREAT COVERAGE. DUE TO
THESE CONCERNS...HAVE REDUCED THE SIZE OF THE 30 PERCENT SEVERE
THREAT PROBABILITY TO FOCUS ON AREAS A BIT FURTHER SOUTH.
Member Since: August 2, 2006 Posts: 46 Comments: 11669
218. Skyepony (Mod)
6:48 PM GMT on March 01, 2014
White Rabbits, White Rabbits, White Rabbits!

Member Since: August 10, 2005 Posts: 173 Comments: 38148
217. 1900hurricane
4:37 PM GMT on March 01, 2014
Ugh...
Member Since: August 2, 2006 Posts: 46 Comments: 11669
216. beell
1:53 PM GMT on March 01, 2014

07Z Day 2 Probabilistic (click for all Outlook graphics)

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1249 AM CST SAT MAR 01 2014

VALID 021200Z - 031200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF EASTERN TEXAS...LOUISIANA...SOUTHERN ARKANSAS...WESTERN AND SOUTHERN MISSISSIPPI...

...SYNOPSIS...
A DEEP CYCLONE CURRENTLY CENTERED OFF THE CNTRL CA COAST WILL HAVE DEVOLVED INTO A SHORTWAVE TROUGH...WHICH WILL ADVANCE FROM THE SRN ROCKIES TO THE MIDDLE MS VALLEY ON D2/SUN. WHILE THIS FEATURE WILL DE-AMPLIFY IN CONFLUENT FLOW ALOFT...DISTURBANCE-PRECEDING ASCENT WILL SUPPORT THE ENEWD PROGRESSION OF A WAVE ALONG THE LEADING EDGE OF SHALLOW ARCTIC AIR FROM N-CNTRL TX TO THE ARKLATEX TO THE CNTRL/SRN APPALACHIANS. A SFC DRYLINE WILL EXTEND S OF THE FRONTAL WAVE OVER CNTRL/SRN TX AND WILL BE OVERTAKEN BY THE ARCTIC AIR ADVANCING SWD BEHIND THE WAVE. E OF THE DRYLINE...A STRENGTHENING LLJ WILL ENCOURAGE THE POLEWARD TRANSPORT OF LOW-LEVEL MOISTURE INTO ERN PORTIONS OF THE SRN PLAINS TO THE LOWER MS VALLEY. SFC ANALYSIS REVEALS THE INITIAL STAGES OF THIS PROCESS...WITH DEWPOINTS IN THE LOWER/MIDDLE 60S PRESENTLY REACHING THE LOWER TX COAST.

...ERN PORTIONS OF THE SOUTHERN PLAINS EWD TO THE LOWER MISSISSIPPI VALLEY...
ISOLATED ELEVATED THUNDERSTORMS -- PERHAPS WITH SVR HAIL -- ROOTED ATOP THE SHALLOW ARCTIC AIR MAY BE ONGOING SUN MORNING ACROSS PARTS OF FAR SRN OK AND NRN TX. SIMILAR ACTIVITY MAY PERSIST AS FAR AS 100-150 MILES /OR MORE/ BEHIND THE SWD/SEWD-MOVING SFC BOUNDARY THROUGH THE PERIOD. THIS WILL OCCUR AS ISENTROPIC ASCENT AND ELEVATED MOISTURE TRANSPORT ACCOMPANYING THE LLJ PERSIST BENEATH H7-H5 LAPSE RATES AROUND 7-7.5 C/KM AND 50-70-KT H5 WSWLY/S.

MEANWHILE...DIURNAL HEATING OF MIDDLE-60S SFC DEWPOINTS BENEATH AN EML PLUME ORIGINATING FROM THE NRN MEXICAN PLATEAU WILL YIELD MODERATE TO LOCALLY STRONG INSTABILITY E OF THE DRYLINE DURING THE AFTERNOON. WHILE THERE IS SOME UNCERTAINTY REGARDING THE COVERAGE OF SFC-BASED CONVECTION...MID-LEVEL HEIGHT FALLS PRECEDING THE SHORTWAVE TROUGH WILL OVERSPREAD THIS INSTABILITY THROUGH THE DAY. THIS WILL BE ASSOCIATED WITH AN INCREASE IN THE CHANCE FOR CONVECTIVE INITIATION IN CLOSER PROXIMITY TO THE SFC FRONT AND ON THE PERIPHERY OF STRONGER CAPPING ACCOMPANYING THE EML PLUME -- I.E. FROM THE ARKLATEX TO NERN/E-CNTRL TX. THIS ACTIVITY WOULD SPREAD EWD/SEWD TO PARTS OF THE LOWER MS VALLEY THROUGH SUN NIGHT AS THE ARCTIC BOUNDARY SHIFTS SEWD...AND WILL YIELD A HIGHER SVR POTENTIAL FROM ERN TX TO LA AND ACROSS FAR SRN AR.

STRONG DEEP SHEAR OWING TO STRENGTHENING MID-LEVEL FLOW WOULD ENCOURAGE THE ORGANIZATION OF SFC-BASED CONVECTION...WITH INITIALLY MIXED SUPERCELL/QLCS MODES OVER ERN TX TRANSITIONING TO MORE LINEAR MODES FARTHER E. DAMAGING WIND GUSTS AND SVR HAIL WILL BE THE PRIMARY CONCERNS WITH THIS ACTIVITY...WITH THE DMGG-WIND POTENTIAL PERHAPS BECOMING OF GREATER CONCERN AS STORMS SPREAD ACROSS PARTS OF LA. STRONG LOW-LEVEL SHEAR BENEATH 40-55 KT OF SWLY H85-H7 FLOW WILL EXIST AND ALSO YIELD SOME POTENTIAL FOR TORNADOES. THERE MAY BE A TENDENCY FOR THE ARCTIC BOUNDARY TO UNDERCUT INITIALLY SFC-BASED CONVECTION. HOWEVER...FAST MID-LEVEL FLOW CONSISTING OF AT LEAST SOME BOUNDARY-ORTHOGONAL COMPONENT S OF THE FRONTAL WAVE MAY MAINTAIN NEAR-SFC-BASED CONVECTION. ANY FRONT-UNDERCUT CONVECTION WOULD STILL SUPPORT A HAIL RISK.

AS THE FRONTAL WAVE DEVELOPS ENEWD AND AWAY FROM RICHER LOW-LEVEL MOISTURE/BUOYANCY WHILE WEAKENING SUN NIGHT...AND THE ARCTIC BOUNDARY PINCHES OFF THE NRN EXTENT OF RETURNING MOISTURE...THE SVR POTENTIAL WILL LESSEN ACROSS ERN PARTS OF THE LOWER MS VALLEY. HOWEVER...SOME SVR POTENTIAL WILL EXIST AS FAR E AS SRN MS AND SERN LA LATE SUN NIGHT AS THE LEADING EDGE OF CONVECTIVELY ENHANCED COLD POOLS INTERCEPT RICHER LOW-LEVEL MOISTURE.

..COHEN.. 03/01/2014
Member Since: September 11, 2007 Posts: 143 Comments: 16726
215. Thunderfan
2:56 AM GMT on March 01, 2014
I thought I would share my local extended forecast. Over on Master's blog, I heard some hype about a southeast storm Friday. Euro was for it, GFS not.

I think WU's forecast was confused by that. Ever seen sleet/freezing rain at 58F? LOL

img src=" photo ScreenShot02-28-14at0952PM_zps319b7295.png">
Member Since: April 14, 2012 Posts: 3 Comments: 801
214. 1900hurricane
12:28 AM GMT on March 01, 2014
Nice to see the WPC throwing the NAM out at the moment, but it certainly looks like it's going to be a tricky forecast.

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
141 PM EST FRI FEB 28 2014

VALID FEB 28/1200 UTC THRU MAR 04/0000 UTC

...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...


12Z MODEL EVALUATION...INCLUDING FINAL PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~

STRONG SYSTEM IN THE SOUTHWEST TONIGHT...REACHING THE PLAINS/OH
VALLEY BY SUN/MON
WAVY FRONTAL BOUNDARY ACROSS THE MID-ATLANTIC SUN/MON
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 12Z GFS/12Z ECMWF
CONFIDENCE: A LITTLE BELOW AVERAGE

THE GREATEST DIFFERENCES ARE IN THE TIMING/AMPLITUDE OF THE
SHORTWAVE AS IT REACHES THE MISSISSIPPI VALLEY SUNDAY NIGHT. THE
12Z NAM APPEARS TO BE AN OUTLIER IN BEING FASTER/WEAKER WITH THE
SRN STREAM SHORTWAVE AND IS THEREFORE CONSIDERED A LOW PROBABILITY
SOLUTION...NEARLY PHASING WITH A PROGRESSING NRN STREAM TROUGH
CROSSING THE GREAT LAKES. THE GFS HAS BEEN TRENDING FASTER/WEAKER
BY MON MORNING...WHILE THE CMC REMAINS THE FARTHEST SOUTH AND
STRONGEST. THE 12Z ECMWF IS SIMILAR TO ITS PREVIOUS RUN WITH THE
SOUTHERN STREAM WAVE...AND SIMILAR TO THE GFS STRENGTH...BUT A
LITTLE SLOWER AND MORE IN THE MIDDLE OF THE MODEL
SPREAD...SUPPORTED BY THE LATEST ENSEMBLE SPAGHETTI HEIGHTS AT 564
DM...WHICH ARE A BIT SLOWER THAN THE 12Z GFS. THE BLEND INCLUDES
THE GFS DUE TO SIMILARITY AT THE SURFACE AND THE PREFERENCE FOR
THE GFS WITH THE NEW ENGLAND SHORTWAVE REFERENCED BELOW WHICH
AFFECTS FRONTAL PLACEMENT.

Member Since: August 2, 2006 Posts: 46 Comments: 11669
213. 1900hurricane
12:19 AM GMT on March 01, 2014
Quoting 209. beell:
May be worth the time to keep up with the NAM and its much deeper push of shallow cold air to the coast underneath a very warm layer (14°C). A chance for some weak isentropic lift/moisture on SW flow to over-run the cold surface air.

Ground temps should warm quite a bit on Sunday-but maybe some issues with freezing drizzle on elevated surfaces for the Monday morning commute in SE/NE TX.

Interesting.

The NAM legitimately scares me, especially with what happened last spring. I really hope it is off base, but it certainly needs to be watched.
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212. Thunderfan
6:47 PM GMT on February 28, 2014
Well, as typical for March - there will be no shortage of weather to talk about.
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211. beell
1:15 PM GMT on February 28, 2014
Somewhat rare to see a risk area for California. May see that 5% tornado rise a bit as the storm system nears the coast. The backed orographic flow is always an interesting feature here (onshore winds turning to the left as they hit the mountains)




DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0630 AM CST FRI FEB 28 2014

VALID 281300Z - 011200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF SRN CA...

...SYNOPSIS...
SPLIT FLOW PATTERN WILL PREVAIL THROUGH EARLY SAT FROM THE EASTERN PACIFIC EWD INTO THE CNTRL U.S...SOUTH OF PERSISTENT BLOCK OVER ERN AK. POTENT UPR LOW IN THE SRN STREAM...NOW LOCATED ABOUT 600 MILES W OF SFO...SHOULD CONTINUE SLOWLY SEWD TODAY/TNGT AND REACH A POINT ABOUT 250 MILES SW OF SFO BY 12Z SAT. IN THE SAME BELT OF FLOW...DOWNSTREAM IMPULSE NOW ENTERING SW OK EXPECTED TO FURTHER WEAKEN AS IT SHEARS ESE ACROSS THE LWR MS VLY THROUGH THIS EVE...AND CONTINUES ESE TO THE S ATLANTIC CST BY THE END OF THE PERIOD.

AT LWR LVLS...DEEPLY OCCLUDED /PER SATELLITE/ SFC LOW ASSOCIATED WITH PACIFIC UPR LOW SHOULD MOVE SEWD IN TANDEM WITH THE UPR SYSTEM. ATTENDANT WARM CONVEYOR BELT WILL AFFECT MUCH OF CA EARLY THIS MORNING...WHILE INCREASINGLY COLD/CYCLONIC FLOW OVERSPREADS CNTRL AND SRN SECTIONS OF THE STATE LATER TODAY THROUGH TNGT. FALLING HEIGHTS...SUFFICIENT MOISTURE...AND ANTECEDENT MILD CONDITIONS SUGGEST A GOOD CHANCE FOR TSTMS OVER MUCH OF CA TODAY...WITH THE THREAT LIKELY TO SPREAD E/SE INTO THE LWR CO VLY EARLY SAT. GIVEN THE ACCOMPANYING WIND FIELD AND POTENTIAL FOR TOPOGRAPHICALLY-FORCED LOW-LVL FLOW...SOME OF THE STORMS COULD BECOME STRONG TO SVR.

...CA TO LWR CO VLY TODAY/TNGT...
MODEST LOW-LVL MOISTURE INFLOW...AND MOISTENING FROM ONGOING WARM CONVEYOR BELT RAINFALL...COUPLED WITH MID-LVL COOLING ASSOCIATED WITH THE CONTINUED SE MOTION OF E PACIFIC UPR LOW...SHOULD FOSTER SUFFICIENT DESTABILIZATION/DEEPENING OF EXISTING CONVECTION TO YIELD THUNDER OVER MUCH OF CNTRL AND SRN CA LATER TODAY INTO TNGT. DESTABILIZATION OVER SRN SECTIONS MAY BE LOCALLY ENHANCED BY PARTIAL CLEARING IN WAKE OF PASSING WARM CONVEYOR BELT CLOUDS. THE STRONGEST MID-LVL COOLING/DESTABILIZATION...HOWEVER...LIKELY WILL NOT OCCUR S OF THE PT CONCEPTION/VANDENBERG AREA UNTIL THE ARRIVAL OF OFFSHORE VORT LOBE /MARKED BE LEADING EDGE OF DEEPER CONVECTION OFF THE CNTRL CA CST/ AFTER 17-18Z.

WHILE SBCAPE LIKELY WILL REMAIN AOB ABOUT 750 J/KG...COMBINATION OF EVEN MODEST BUOYANCY WITH INCREASING ASCENT AND STRONG /60 KT/ SSW TO SWLY DEEP SHEAR IN EXIT REGION OF 80 KT 500 MB JET STREAK ACCOMPANYING THE VORT LOBE SHOULD PROMOTE SOME DEGREE OF LOW TO MID-LVL ROTATION IN ANY LONGER-LIVED UPDRAFTS. COUPLED WITH OROGRAPHIC BACKING OF THE LOW-LVL FLOW...ESPECIALLY IN THE LOS ANGELES BASIN...SETUP MAY YIELD A FEW STORMS WITH TORNADOES IN ADDITION TO MARGINALLY SVR HAIL. A MORE CONDITIONAL SVR THREAT MAY DEVELOP IN THE SAN JOAQUIN VLY...WHERE MOISTURE AND HEATING ARE EXPECTED TO BE MORE LIMITED.

STRENGTH OF FORCING FOR ASCENT AND PROGRESSIVE NATURE OF UPR SYSTEM SUGGEST THAT THE CONVECTION/STORMS ULTIMATELY WILL MERGE INTO ONE OR MORE BROKEN LINES BY LATE AFTN. THIS ACTIVITY MAY MOVE OR REDEVELOP E INTO THE LWR CO VLY TNGT AND EARLY SAT...WHERE STRONG LOW-LVL WINDS/SHEAR IN A SOMEWHAT DRIER LOW-LVL ENVIRONMENT COULD POSE A CONTINUED RISK FOR SVR WIND AND POSSIBLY A BRIEF TORNADO INTO THE NIGHT.

..CORFIDI/MARSH.. 02/28/2014
Member Since: September 11, 2007 Posts: 143 Comments: 16726
210. beell
12:11 PM GMT on February 28, 2014
Just in-time forecating on the HWO.

I like the sea fog also. We were about to get out of the season with warming shelf waters. This next push of cold will drop those water temps back down a notch or two and prolong our sea-fog season.

Some good web cams from Galveston here for watching the ebb and flow of the fog

And it's Mardi Gras weekend down there so you may see something besides fog!

Time to make the donuts. Will be making them Saturday as well. Later.

Member Since: September 11, 2007 Posts: 143 Comments: 16726
209. beell
12:03 PM GMT on February 28, 2014
May be worth the time to keep up with the NAM and its much deeper push of shallow cold air to the coast underneath a very warm layer (14°C). A chance for some weak isentropic lift/moisture on SW flow to over-run the cold surface air.

Ground temps should warm quite a bit on Sunday-but maybe some issues with freezing drizzle on elevated surfaces for the Monday morning commute in SE/NE TX.

Interesting.
Member Since: September 11, 2007 Posts: 143 Comments: 16726
208. Thunderfan
11:59 AM GMT on February 28, 2014
Your HWO is more interesting today. Always been fascinated by sea fog as well.
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207. beell
11:12 AM GMT on February 28, 2014
Lookin' good,1900. Maybe some slight adjustments to the north based on the cap and the undercutting issue.

I still like your risk area fwiw!
Member Since: September 11, 2007 Posts: 143 Comments: 16726
206. beell
11:08 AM GMT on February 28, 2014

0830Z Day 3 Probabilistic Outlook (click image for all Outlook graphics)

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0221 AM CST FRI FEB 28 2014

VALID 021200Z - 031200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF EASTERN TEXAS...LOUISIANA...SOUTHERN ARKANSAS...WESTERN MISSISSIPPI...

...SYNOPSIS...
A MID-LEVEL SHORTWAVE TROUGH IN THE SRN STREAM WILL ADVANCE FROM THE SRN ROCKIES TO THE MIDDLE MS VALLEY WHILE DE-AMPLIFYING IN CONFLUENT FLOW ALOFT. ASCENT PRECEDING THIS DISTURBANCE WILL ENCOURAGE THE ENEWD PROGRESSION OF A FRONTAL WAVE FROM N-CNTRL TX TO THE ARKLATEX TO THE TN VALLEY ALONG THE LEADING EDGE OF SHALLOW ARCTIC AIR. A SFC TROUGH/DRYLINE WILL EXTEND S OF THE FRONTAL WAVE OVER CNTRL/SRN TX AND WILL BE OVERTAKEN BY THE ARCTIC AIR ADVANCING SWD ON THE BACKSIDE OF THE WAVE. E OF THE DRYLINE...A LLJ WILL ENCOURAGE THE NWD TRANSPORT OF RICHER GULF MOISTURE INTO ERN PORTIONS OF THE SRN PLAINS TO THE LOWER MS VALLEY -- ORIGINATING FROM A RESERVOIR OF 1.5-1.8-INCH PW CURRENTLY OVER THE BAY OF CAMPECHE PER GPS DATA.

...ERN PORTIONS OF THE SOUTHERN PLAINS EWD TO THE LOWER MISSISSIPPI VALLEY...
ISOLATED STORMS...PERHAPS WITH MARGINALLY SVR HAIL...MAY BE ONGOING AT THE BEGINNING OF THE PERIOD ACROSS PARTS OF FAR SRN OK AND NRN TX AS WARM ADVECTION CONTINUES ATOP THE SHALLOW COLD DOME. MEANWHILE...THE INFLUX OF MIDDLE/UPPER 60S SFC DEWPOINTS E OF THE DRYLINE BENEATH AN EML PLUME EMANATING FROM THE NRN MEXICAN PLATEAU IS EXPECTED TO RESULT IN MODERATE INSTABILITY FROM THE ARKLATEX INTO E-CNTRL TX BY MID-DAY. AS MID-LEVEL HEIGHT FALLS PRECEDING THE SHORTWAVE TROUGH OVERSPREAD DIURNALLY ENHANCED BUOYANCY...SFC-BASED CONVECTION WILL LIKELY FORM ALONG THE FRONT AND ON THE PERIPHERY OF STRONGER CAPPING ACCOMPANYING THE EML PLUME -- I.E. FROM THE ARKLATEX TO NERN/E-CNTRL TX -- BY MID-AFTERNOON. THIS ACTIVITY WILL SPREAD EWD/SEWD TO PARTS OF THE LOWER MS VALLEY THROUGH SUN NIGHT...WHILE THE SEWD ADVANCE OF THE ARCTIC BOUNDARY PINCHES OFF MOIST SLY LOW-LEVEL TRAJECTORIES ON THE WARM SIDE OF THE FRONTAL WAVE AND EXTENDS THE SVR POTENTIAL TO THE COAST.

STRONG DEEP SHEAR OWING TO 50-70 KT OF H5 WSWLY/S WILL ASSIST STORM ORGANIZATION...WITH INITIALLY MIXED SUPERCELL/QLCS MODES OVER ERN TX TRANSITIONING TO MORE LINEAR MODES FARTHER E. DAMAGING WIND GUSTS...AND SVR HAIL JUST AFTER SFC-BASED CONVECTIVE INITIATION...WILL BE THE PRIMARY CONCERNS WITH THIS ACTIVITY. THE GREATEST POTENTIAL FOR SVR STORMS WILL EXTEND FROM ERN TX TO NRN/CNTRL LA...WHERE STRONG LOW-LEVEL SHEAR BENEATH 40-55 KT OF SWLY H85-H7 FLOW WILL EXIST AND ALSO YIELD SOME POTENTIAL FOR TORNADOES. AS THE FRONTAL WAVE DEVELOPS ENEWD AND AWAY FROM RICHER LOW-LEVEL MOISTURE/BUOYANCY WHILE WEAKENING SUN NIGHT...THE SVR POTENTIAL WILL BECOME INCREASINGLY MARGINAL ACROSS ERN PARTS OF THE MS VALLEY.

..COHEN.. 02/28/2014
Member Since: September 11, 2007 Posts: 143 Comments: 16726
205. 1900hurricane
11:27 PM GMT on February 27, 2014
My circle from yesterday isn't looking so bad at the moment!



AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
351 PM CST THU FEB 27 2014

.DISCUSSION...
HIGH PRESSURE OVER THE AREA SLIDING EAST WHICH HAS GIVEN THE AREA
A NICE COOL AND DRY AFTERNOON. THE HIGH CONTINUES EAST ON FRIDAY
AND AN UPPER LEVEL DISTURBANCE OVER THE FOUR CORNERS AREA THIS
AFTERNOON SWINGS EAST ALONG THE RED RIVER. THIS SHOULD PUSH A
PACIFIC FRONT INTO THE HILL COUNTRY WITH MOST IF NOT ALL OF SETX
CAPPED. PERHAPS THE FAR NORTHEAST AREAS MAY GET SOMETHING OTHER
THAN SPITS OR SPRINKLES ON FRIDAY BUT LIGHT NONETHELESS WITH THE
WARMING TREND CONTINUING. SEA FOG THREAT RETURNING LATE FRIDAY
AND SATURDAY. SATURDAY SHOULD BE VERY WARM WITH STRONG INVERSION
ALOFT AND SHALLOW LAYER BELOW THAT SHOULD WARM INTO THE MID TO
UPPER 70S FOR MOST AREAS. NEXT TROUGH IN THE SEQUENCE DEEPENING AS
IT MOVES INTO CA AND THEN TOWARD THE 4 CORNERS AREA SUNDAY
MORNING...IT BEGINS TO SHEAR SLOWLY BUT IMPRESSIVE MOISTURE IS
FORECAST TO SURGE BACK INTO THE AREA SUNDAY AND FUEL THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. GFS/ECMWF AND EVEN THE
NAM ALL ARE HIGHLIGHTING AN AREA OF STRONG TO SEVERE THUNDERSTORMS
LATE SUNDAY OVER THE NORTHEASTERN AREAS (MADISONVILLE TO CONROE TO
LIBERTY) FOR TORNADOES OR STRAIGHT LINE DAMAGING WINDS
WHERE
STORMS GET AWAY FROM THE NOSE OF THE CAP THAT WILL INTRUDE INTO
THE AREA FROM THE SOUTHWEST (STRONG CAP IN THE SW AREAS). WILL
CONTINUE TO SHOW 30-50 POPS FOR NOW BUT MAY NEED A NUDGE UP AS IT
GETS CLOSER. QPF OF 0.25 TO 0.50 IS LIKELY OVER MUCH OF THE CWA
(EXCEPT PERHAPS SW COUNTIES) AND WOULDN`T BE SHOCKED IF FAST
MOVING STORM DUMP 1-3 INCHES IN THE NE COUNTIES. BLAST OF CANADIAN
AIR SWEEPS THROUGH WITH THE STORMS AND THE AREA SHOULD DRY OUT
MONDAY AND POSSIBLY TUESDAY UNLESS NEXT S/W IS STRONG ENOUGH TO
BRING BACK SOME LIGHT RAIN TO THE SOUTHERN AREA WITH GOOD UPGLIDE.
45
Member Since: August 2, 2006 Posts: 46 Comments: 11669
204. 1900hurricane
5:25 PM GMT on February 27, 2014
I've seen worse...

Member Since: August 2, 2006 Posts: 46 Comments: 11669
203. Barefootontherocks
3:59 PM GMT on February 27, 2014
PS.

19,
Guess I thought that is SOP. Norman issues an Hazardous Weather Outlook twice a day, 5 a.m. and noon, every day, but then... this is Oklahoma. lpl

Nvmnd. Deflecting you to bl at 199.
Member Since: April 29, 2006 Posts: 154 Comments: 18715
202. Barefootontherocks
3:49 PM GMT on February 27, 2014
Quoting 187. beell:
Well, I did find a reference to a "ball bearing mousetrap"-but other than that, I must have missed something somewhere.
:-}
Yeah. My comment altogether.

fwiw, Norman's calling this a "fairly stout upper level storm system." Probably gonna get ice/wintry whatever here. Meow.

bf out!

10:52 cst Instead of another comment, will ADD here. From wiki article on ball bearing:
"The calculated life for a [ball] bearing is based on the load it carries and its operating speed... standard usable bearing lifespan is inversely proportional to the bearing load cubed."

Common ball bearing types:
Angular contact
Deep grove
Axial
Slot fill
Caged
Self aligning

The Wiki ball bearing article suggests see also...
Ball screw
Bearing (mechanical)
Bearing Specialists Association
Brinneling, a common failure mode
Linear bearing
Thrust bearing
Spherical roller bearing

Since my natural speed is slow and my lifespan, alas inversely proportional to the ball bearing load, is too short (tempered) for comfort, guess I'll brinnel away...
Member Since: April 29, 2006 Posts: 154 Comments: 18715
201. beell
1:41 PM GMT on February 27, 2014
I'm sure you would have, Linda-80 chains to the mile (statute)!

I have actually touched a chain but never used one in the field. Do know my way around a theodolite and more recently (10 yrs), sub-meter accuracy with post-survey processed GPS data!

Member Since: September 11, 2007 Posts: 143 Comments: 16726
200. Thoughtsteader
12:52 PM GMT on February 27, 2014
Thanks for that info about the chains, beell. I might have gotten there eventually, but now I am there and have a starting point for figuring out how Sibley and his crew did what they did. I see it involves math. I'll try not to freak out.

And I'm glad to see rain projected for the weekend. It would be lovely if we could fall into that pattern for a while. I appreciate how self-centered that is, but I speak for a small cadre of workers who can't get into the danged marinas on the weekends. ;)
Member Since: January 16, 2014 Posts: 35 Comments: 516
199. beell
11:36 AM GMT on February 27, 2014
Our daily HWO Product page.

HGX HWO
Member Since: September 11, 2007 Posts: 143 Comments: 16726
198. beell
11:25 AM GMT on February 27, 2014
Ship it!

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0347 AM CST THU FEB 27 2014

VALID 021200Z - 071200Z

...DISCUSSION...
SUNDAY /DAY 4/ MODELS HAVE TRENDED TOWARD THE ECMWF REGARDING THE TIMING AND AMPLITUDE OF A SHORTWAVE TROUGH THAT WILL MOVE THROUGH THE SRN PLAINS AND LOWER MS VALLEY AREA. PRECEDING THIS FEATURE AN ARCTIC FRONT WILL ADVANCE SWD INTO A PORTION OF THE SRN PLAINS AND LOWER MS VALLEY. LOWER VERTICAL RESOLUTION SPECTRAL MODELS TEND TO BE A BIT SLOWER WITH SHALLOW ARCTIC SURGES...SO THE SOMEWHAT FASTER NAM SOLUTION MAY BE REASONABLE. BY 12Z SUNDAY THIS BOUNDARY WILL LIKELY EXTEND FROM NRN AR SWWD INTO NWRN TX AND ADVANCE TO SCNTRL TX INTO NRN LA EARLY SUNDAY EVENING.

DEWPOINTS IN THE UPPER-MID 60S WILL HAVE ADVECTED THROUGH THE TX PRE-FRONTAL WARM SECTOR WITH LOW-MID 60S EXPECTED FARTHER EAST INTO THE LOWER MS VALLEY. MODERATE INSTABILITY MAY RESIDE OVER NWRN AND NCNTRL TX WED MORNING WHERE RICHER MOISTURE WILL HAVE ADVECTED BENEATH STEEPER LAPSE RATES...BUT ATMOSPHERE IN THIS REGION MAY REMAIN CAPPED. STORMS MAY INITIATE ALONG THE FRONT OVER NCNTRL TX DURING THE MORNING AND SUBSEQUENTLY DEVELOP SEWD THROUGH ERN TX...REACHING THE LOWER MS VALLEY BY EVENING. WINDS IN THE SFC-700 MB LAYER ARE INITIALLY EXPECTED TO BE MODEST...BUT WITH VERTICAL SHEAR THROUGH A DEEPER LAYER OF 40 KT. A FEW STORMS FROM NCNTRL THROUGH ERN TX MAY POSE A THREAT FOR ISOLATED LARGE HAIL AND DAMAGING WIND...THOUGH THERE MAY BE SOME TENDENCY FOR ANY STORMS DEVELOPING ON THE FRONT TO BE UNDERCUT WHICH WOULD MITIGATE THE WIND THREAT.

OVERNIGHT...THE LLJ IS FORECAST TO STRENGTHEN OVER THE LOWER MS VALLEY WHERE INSTABILITY WILL BE SOMEWHAT WEAKER. SOME THREAT WILL PERSIST FOR ISOLATED DAMAGING WIND GUSTS ALONG WITH A CONDITIONAL THREAT FOR A TORNADO...BEFORE ACTIVITY BEGINS TO OUTRUN MOIST AXIS LATER SUNDAY NIGHT.

WHILE AN INTRODUCTION OF AT LEAST A LOWER END SLIGHT RISK AREA IS PROBABLE IN LATER UPDATES...CONFIDENCE IS NOT SUFFICIENT AT THIS TIME TO DELINEATE A 30% OR GREATER COVERAGE AREA. BEYOND DAY 4 OVERALL SEVERE POTENTIAL APPEARS LOW UNTIL POSSIBLY DAY 8 ACROSS FL.
Member Since: September 11, 2007 Posts: 143 Comments: 16726
197. 1900hurricane
3:25 AM GMT on February 27, 2014
I don't have a problem with HGX failing to mention Sunday's possible event in the HWO; it is five days out after all. It's just curious that they even issued one at all if there are no hazards to monitor.
Member Since: August 2, 2006 Posts: 46 Comments: 11669
196. Thunderfan
3:02 AM GMT on February 27, 2014
Quoting 195. beell:
Well, in their defense, it is an outlook. Similar to SPC's "NO SVR TSTMS FCST".


Well, okay...
Member Since: April 14, 2012 Posts: 3 Comments: 801
195. beell
2:53 AM GMT on February 27, 2014
Well, in their defense, it is an outlook. Similar to SPC's "NO SVR TSTMS FCST".
Member Since: September 11, 2007 Posts: 143 Comments: 16726
194. Thunderfan
1:38 AM GMT on February 27, 2014
I think I understand...

understand 1900 that is...

Severe Weather Statement

There is no severe weather currently.

Thank you...
Member Since: April 14, 2012 Posts: 3 Comments: 801
193. beell
1:26 AM GMT on February 27, 2014
Who you gonna believe, 1900? Your own convection-allowing understanding or a text product with a CWA focus 4 days out?

Hey, it never looked like the end of the world. If we get some focused severe-warned thunder inside your polygon-it's a win!

It may be better if we never know, Tf!
Member Since: September 11, 2007 Posts: 143 Comments: 16726

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