More Pennsylvania severe weather...

By: Zachary Labe , 4:57 PM GMT on June 03, 2008

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"Thoughts on Severe Weather Outbreak of June 2-3"
Another interesting storm setup is headed our direction with potential for severe weather across almost all regions of Pennsylvania for some point within the next three day. But first off I want to talk about the severe weather from May 31 on Saturday. Many people I know are very curious about what went wrong for not having the widespread severe weather. Well let me start off with forecasts. The Storm Prediction Center in Norman, Oklahoma issued a rare moderate risk for eastern Pennsylvania with a 45% chance of wind damage, 30% chance of severe hail, and even an impressive 10% chance of tornadoes. Then the rest of the state was under a slight risk for severe weather. Overnight Friday severe weather developed across the Ohio Valley with around 20 tornadoes reported. The supercells in that region joined together to form an mesocyclone thunderstorm complex that then pushed its way into western Pennsylvania by around five in the morning. A tornado watch was issued for western Pennsylvania. The MCS slowly moved across Pennsylvania and never ended up weakening. Strong dynamics were available that were near extremely impressive standards. Shear and helocity indices were sky high and EHI values were high too. But yet the MCS threw clouds across the entire region near the system and to the north. This meant anyone north of the Mason-Dixon line in Pennsylvania was socked in cloud cover most of the day. To the south in Maryland and Virginia severe weather broke out with mainly wind damage and hail. But one confirmed tornado and two unconfirmed tornadoes were reported in Maryland. Later in the day the MCS moved south of Pennsylvania allowing sun to break out, especially in the north. Now remember the MCS was located along the warm front. So the cold front followed in later in the day creating two areas of concentrated severe weather mostly located in northern Pennsylvania. An intense line of thunderstorms became very organized over the Poconos and isolated severe thunderstorms occured across northwestern Pennsylvania. Evening was fast approaching and most of the severe weather then dissapated quickly before affecting southern Pennsylvania. Southern Pennsylvania, which had the most impressive storm dynamics, was skipped for severe weather due to the morning MCS complex. Forecasts for every station, NWS, Storm Prediction Center, and myself had made pretty poor forecasts. But overall though I was not too upset as each of my moderate/high risks were under a tornado watch at some point. And across northern Pennsylvania severe weather reports did come in. Overall I give myself a somewhat satisfactory job. Below is my forecast map against the actual storm reports and the actual warnings that went out. Now for more information on the current June 3-4 severe weather see other sections below for more information.


"Current Weather Setup"
Alright another relatively complicated weather setup is headed towards Pennsylvania. Why can it never be plain and simple? O well it is only everchanging weather. Anyway moisture is on the increase across Pennsylvania with PWATS already around 1.4inches in extreme western Pennsylvania. But later tonight 4-5 deviation above normal PWATS will move into the region. The Low-level jet will also focus in moisture souring up from the Gulf of Mexico. The warm front and cold front are going to become stationary across the region as shortwaves and vortexes of precipitation move in across the region. It appears as if there will be three rounds of precipitation. First round will be Tuesday afternoon where thunderstorms are forming across areas of Pennsylvania as instibilities aloft are increasing along with at the surface. CAPE values look to approach 1000 j/kg in southern Pennsylvania today with high helicity values and 850 winds remain around 50+ knots. Freezing levels look to be around 10,000ft so hail remains to be a threat. Later Tuesday night a vortex will move in along the warm front and there will be a MCS along with it. The models are as typical suffering from convective feedback issues, but it appears as if tonight a MCS will develop across northern Illinois and track across Indiana and Ohio before moving into Pennsylvania after midnight. Overnight upper level instibility will remain high and continue to leave the oppurtinity for severe thunderstorms across some areas at the front-end of the MCS. But the MCS will be in a weakening phase. It appears as if heavy rain will be the main threat as mid-level isentrophic lift is high and PWATS are high. Southern Pennsylvania may be able to squeeze out 1inch of rain. By tomorrow morning the MCS will be weakening. Again then we are faced with another tough question. How fast can things clear out? Based on what past history has shown us this year it appears as if clouds look to prevail for the most part. Still it appears though another round of thunderstorms will form in Ohio and track along with stalled front. A few severe thunderstorms may be a threat, but overall dynamics are not there for anything widespread. High temperatures may stay below 80degrees for most areas along with dewpoints in the low 70s. Alot of questions remain for the setup of the MCS Tuesday night and early Wednesday morning and there is a big bust factor. I now want to highlight the past history of this storm.

A cold front began to push into the inner-mountain west region on Sunday and began to drop a low pressure along with it. A warm front then lifted northward and severe thunderstorms broke out with the main threat of large hail and two tornado reports. Hail with the diameter of 4.25inches was reported in parts of the northwestern Great Plains on Sunday. Then the system moved eastsoutheast and more severe weather broke out for Monday with several areas of MCS's. A strong one developed across Kansas and moved into Missouri. That MCS showed even derecho like features. Overall 3 tornadoes were reported along with around 250 severe weather reports mostly hail. So far today there have been several MCS areas with one that moved from Illinois through Indiana and now into Ohio with over 50 reports of severe weather with that impressive bow echo and one tornado report also. More convection is expected to break out later today.

"Current Advisories"


"Current Satellite"

(Courtesy of Penn State Meteorology.)

"Current Surface Map and Weekly History of Jet Stream Position"


"Radar for Western Pennsylvania"

"Radar for Central Pennsylvania"

"Radar for Eastern Pennsylvania"


"Forecasts from Storm Prediction Center"
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0759 AM CDT WED JUN 04 2008

...MID ATLANTIC REGION...
BOUNDARY LAYER MOISTURE IS WELL-ESTABLISHED OVER THE MID ATLANTIC
REGION...S OF STNRY FRONT EXTENDING EWD FROM CNTRL PA TO NEAR NYC.
FARTHER S...A WEAK OUTFLOW BOUNDARY FROM OVERNIGHT STORMS ATTM
EXTENDS FROM N OF CRW ESE TO N OF RIC. SATELLITE DATA SUGGEST THAT
MODERATE TO LOCALLY STRONG HEATING WILL OCCUR OVER WV/VA/MD AND DE.
GIVEN MOISTURE AVAILABILITY AND FAIRLY STEEP MID-LVL LAPSE
RATES...THIS SHOULD YIELD SBCAPE TO AOA 2000 J/KG...WITH SLIGHTLY
GREATER VALUES POSSIBLE NEAR THE I-95 CORRIDOR.

UPSTREAM...MCV NOW OVER SRN IND EXPECTED TO CONTINUE E AT ABOUT 40
KTS...REACHING NRN WV AROUND 18Z. COMBINATION OF MCV-INDUCED
ASCENT...AND UPLIFT ALONG FRONT...OUTFLOW BOUNDARY AND THE HIGHER
TERRAIN...SHOULD RESULT IN FAIRLY WIDESPREAD STORM COVERAGE AS
HEATING DESTABILIZES REGION LATER TODAY.

WIND PROFILES WILL FEATURE 40+ KT DEEP...UNIDIRECTIONAL WLY
FLOW...WITH MINIMAL CLOUD-LAYER SHEAR. THIS SUGGESTS THAT WHILE
SEMI-DISCRETE STORMS/POSSIBLE SUPERCELLS MAY OCCUR...ESPECIALLY
ALONG THE AFOREMENTIONED BOUNDARIES...THE MAIN OVERALL
ORGANIZATIONAL MODE OF THE CONVECTION SHOULD BE FORWARD-PROPAGATING
LINES. EMBEDDED STORMS COULD YIELD DMGG WIND...SVR HAIL AND PERHAPS
A COUPLE TORNADOES THROUGH EARLY EVENING...BEFORE MOST OF THE
ACTIVITY MOVES OFFSHORE/WEAKENS.

IN THE WAKE OF THE ABOVE CONVECTION...ADDITIONAL WAVES OF WEAKER
STORMS MAY PERSIST OVER NRN PARTS OF THE MID ATLANTIC STATES THROUGH
EARLY THURSDAY.

"Tornado Risks"

"Hail Risks"

"Wind Risks"


"Model Analysis"
Well time to look at the models and looks at their agreements and discrepancies. Overall the models are handling our severe weather situation very poorly. The NAM especially is having some major convective feedback issues. The GFS is very modest with instibility. And the ever trustworthy SREF is highest in terms of instibility levels. I am very impressive by CAPE values from the 9z SREF model in which it shows values over 2000 j/kg in southern Pennsylvania. That combined with high max helicity and modest shear values may result in severe weather tomorrow. As I mentioned earlier it looks like three rounds of storms. The first round this evening. Second round after midnight. And third round tomorrow afternoon. This all makes it very difficult to get a good grab on the forecast. It was hard deciding on what model to focus on, but I decided to use the SREF due to its good record. Also it appears the old fashioned method, lol, meteorological surface observations may come in handy tonight, and Wednesday. The SWEAT index from the GFS though is impressive in southcentral Pennsylvania with it at 250. Below are some maps I felt that were necessary and may come in handy. Also forecast PWATS tonight and tomorrow may approach an impressive 2inches in southern Pennsylvania so flash flooding may be a threat. It will be interesting to watch that unfold. Some areas may see in excess of 2inches of rain in some favored upsloping precipitation regions. That winner may be Franklin County which has already picked up possibly 1.5inches according to rainfall estimates and it is only the beginning of this quite long event. Also below is the high resolution NMM model which appears to be handling the situation pretty well and it shows widespread thunderstorms tomorrow. Below in my forecast section I will take about some of the inhibiting factors, though, of the potential severe weather.

"9z SREF Model Forecast Max Cape Index"

(Wednesday afternoon)

"0z GFS Model Forecast Helicity"

(Wednesday morning)

"12z NAM Model Forecast CAPE and SWEAT indices"

(Wednesday afternoon)

"0z NMM Model Forecast Simulated Future Radar"

(Wednesday afternoon)

"My Forecast for Severe Weather"
Alright well here is my forecast for the upcoming severe weather. Alot of uncertainty remains and I believe cloud cover might preclude most chances of severe weather tomorrow. Still I left though a slight risk out for southern Pennsylvania. Isolated tornadoes are a threat for tonight and tomorrow morning when helicity and shear values remain high. EHI values are not too impressive, but they are still pretty high for Pennsylvania standards at around 2 for western Pennsylvania. I believe wind damage is the primary threat along with maybe some hail in the strong storms capable of the most powerful updrafts. Flash flooding also appears to be a pretty big threat at PWATs are an impressive 2inches for southcentral Pennsylvania. That combined with the typical Blue Ridges upsloping effect will lead to heavy rain amounts isolated at almost 3inches in some areas. I was going to issue a rain map, but I just did not have the time today. Anyway overall this does not appear to be that major of a severe weather threat, but still it needs to be monitored for any possible severe weather associated overnight with the MCS that will move through western Pennsylvania then into southern Pennsylvania slowly dying out by mid tomorrow morning. I will not be adding updates throughout the night. But my maps that update automatically should be enough warning along with the radars. Be sure to turn on your NOAA weather radio before you go to bed as these MCS will move in late overnight and may pose some severe weather problems especially for western Pennsylvania. Have a great evening!!!


(Wednesday)

"Conclusions on Severe Weather Outbreak"
It will be interesting to see what happens with the severe weather threat and the MCS threat for Tuesday night and Wednesday. There are some major convective issues with the models today and the plain meteorological maps show me a possible bust with the energy being stolen to our south. But still I will continue with my forecast for the MCS complex to move across Pennsylvania Tuesday night and then for a break with another round and threat for later on the day Wednesday. I also quickly want to explain my severe weather maps. My risk area definitions are very different than that of the Storm Prediction Center's official risk definitions. I make my risks based on our climate and how widespread severe weather has been in our region for the year so far. For example a moderate risk of severe with by the SPC in Oklahoma might not have the same meaning as it would here in Pennsylvania because it is rare here so the impact level to people is risen. My threats are usually one above what they would be from the SPC due to the fact of severe weather is not overally common in Pennsylvania. My 75% risk of regular thunderstorms translates to 10% risk of severe weather. My slight risk of severe weather translates to 20% chance of severe weather. My moderate risk of severe weather translates to 30% of severe weather. And my high risk of severe weather translates to 40% of severe weather. Overall I hope this better explains my severe weather maps that I produce. And once again this June 3-4 severe weather outbreak does not look to impressive other than just some isolated reports, maybe though a little more widespread across western Pennsylvania. Also as usuall verficition forecast maps will be issued to recap the event for June 3 and June 4. Have a great Tuesday evening!!!

"Storm Reports"


"Here north of Harrisburg 2008 statistics"
(Severe Weather Stats...)
Severe Thunderstorm Watches- 0
Severe Thunderstorm Warnings- 1
Tornado Watches- 1
Tornado Warnings- 0
Total Thunderstorms- 12

(Precipitation Stats...)
Flood Watches- 4
Flood Warnings- 3
Monthly Precipitation- 0.42inches
Yearly Precipitation- 18.49inches

(Temperature Stats...)
Heat Advisories- 0
Excessive Heat Warnings- 0
90degree days- 0

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56. Zachary Labe
12:19 AM GMT on June 05, 2008
A tornado has been reported at an I-95 intersection in Virginia near Charlotte Hall.

Another tornado reported near Bel Alton in Maryland.

Seek shelter now!


***New blog coming early tomorrow morning on the severe weather expected in Pennsylvania again.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
55. TheRasberryPatch
11:28 PM GMT on June 04, 2008
since yesterday evening i got 0.75" of rain with 0.08" for today.
did have a bit of steady rain when the severe weather was south. i am suprised it wasn't more than 0.08".
Member Since: January 26, 2007 Posts: 72 Comments: 6233
54. Zachary Labe
11:02 PM GMT on June 04, 2008
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
650 PM EDT WED JUN 4 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
WESTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
CENTRAL MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...


* UNTIL 1045 PM EDT

* AT 645 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED BETWEEN
1.50 AND 2.00 INCHES OF RAIN HAD FALLEN OVER PORTIONS OF WESTERN
BUCKS COUNTY AND CENTRAL MONTGOMERY COUNTY. ADDITIONAL RAIN IS ON
THE WAY. FLOODING OF POOR DRAINAGE AREAS CAN BE
EXPECTED...ESPECIALLY NEAR HORSHAM...IVYLAND...RICHBORO...
WARRINGTON AND WILLOW GROVE.

LAT...LON 4034 7544 4037 7497 4013 7493 4019 7547
TIME...MOT...LOC 2250Z 296DEG 14KT 4022 7532
Member Since: December 14, 2007 Posts: 278 Comments: 15045
53. Zachary Labe
10:29 PM GMT on June 04, 2008
TheRasberryPatch- That bow echo was impressive. Nothing like that should be expected here at our location. But spotty showers and thunderstorms can be expected all night.

PalmyraPunishment- I know it really angers me. This is the second time they posted a tornado watch in PA only to cancel it within 2 hours. For both watches also they were not necessary as it was obvious the air here in Pennsylvania has been stable even stable aloft for the most part. But if you are going to post a watch I think you should let it expire with its original time for the just-in-case factor.

MDFirefighter- PWATS are very high so rain is going to be very heavy. Last night I had a 5.5inch rain rate for a few minutes. How was the lightning/thunder? Thousands of lightning strikes were reported in Maryland by radar estimates.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
52. MDFirefighter
8:41 PM GMT on June 04, 2008
I don't think I've ever seen it rain that hard. We couldn't even see out of the window here at work. Sky is still VERY dark.
Member Since: February 11, 2006 Posts: 1 Comments: 1201
51. PalmyraPunishment
8:41 PM GMT on June 04, 2008
You know... this is the same diatribe I have against the NWS during the winter, but I'm going to wage it again today.

Why in the world, would you go to the bother of posting a tornado watch for the area -- only to cancel said advisory with 5.5 hours before the watch was to expire?

First off -- in most places, you're going to create slight panic by just posting an advisory alone. In doing that, you would assume that making sure people have an understanding of what is going on, and what is really going to happen, would be paramount.

Secondly -- it's 4:35 PM, and they canceled the advisory at what, 4:00? - what's to say a storm couldn't pop up and drop an actual tornado? Now... if it were to happen, and you drop an advisory off, you run risk of nobody taking heed because you posted an advisory earlier, and canceled it early (this happened last saturday as well). Thus putting people's lives in Jeopardy.

I thought this was just going on during the winter, but clearly I am wrong. I just don't see how the National Weather Service is actually providing a service to the people in doing this... maybe it's just me?
Member Since: January 31, 2007 Posts: 9 Comments: 2250
50. TheRasberryPatch
8:00 PM GMT on June 04, 2008
are we looking at severe weather like this the rest of the day Blizz.

that bow in the radar 30 mins ago was impressive
Member Since: January 26, 2007 Posts: 72 Comments: 6233
49. Zachary Labe
7:55 PM GMT on June 04, 2008
1905 FALLS CHURCH CITY OF FALLS CHU VA 3888 7717 TORNADO TOUCHDOWN REPORT AT ANNANDALE ROAD (LWX)
Member Since: December 14, 2007 Posts: 278 Comments: 15045
48. Zachary Labe
7:37 PM GMT on June 04, 2008
New tornado warning out for counties just south of Annapolis, MD.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
47. MDFirefighter
7:36 PM GMT on June 04, 2008
Tornado spotted in Falls Church, VA. Take cover if you're in that area or in the path of that storm.
Member Since: February 11, 2006 Posts: 1 Comments: 1201
46. Zachary Labe
7:30 PM GMT on June 04, 2008
Northern Suburbs of DC...

MDC003-027-031-033-042000-
/O.NEW.KLWX.TO.W.0015.080604T1920Z-080604T2000Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
320 PM EDT WED JUN 4 2008

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* TORNADO WARNING FOR...
WEST CENTRAL ANNE ARUNDEL COUNTY IN CENTRAL MARYLAND...
SOUTHEASTERN HOWARD COUNTY IN CENTRAL MARYLAND...
SOUTHEASTERN MONTGOMERY COUNTY IN CENTRAL MARYLAND...
NORTHERN PRINCE GEORGES COUNTY IN CENTRAL MARYLAND...

* UNTIL 400 PM EDT

* AT 316 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM WITH STRONG ROTATION NEAR WHITE OAK...MOVING
EAST AT 43 MPH.

* LOCATIONS IMPACTED INCLUDE...
BELTSVILLE...
HILLANDALE...
ADELPHI...
COLLEGE PARK...
GREENBELT...
LAUREL...

IF YOU ARE NEAR THE PATH OF THIS STORM...TAKE COVER NOW! IF NO
UNDERGROUND SHELTER IS AVAILABLE MOVE TO AN INTERIOR ROOM ON THE
LOWEST FLOOR. MOBILE HOMES AND VEHICLES SHOULD BE ABANDONED FOR MORE
SUBSTANTIAL SHELTER. AVOID WINDOWS!

DO NOT TAKE SHELTER UNDER HIGHWAY OVERPASSES!

LAT...LON 3920 7676 3896 7671 3900 7708 3912 7712
TIME...MOT...LOC 1920Z 274DEG 37KT 3903 7701
Member Since: December 14, 2007 Posts: 278 Comments: 15045
45. PalmyraPunishment
7:26 PM GMT on June 04, 2008
blizz - yeah... sucks. why does weather have to such in pennsylvania anymore? lol

if it's going to be stormy... dammit be stormy.

i wonder if the hype-meter on accuweather's forums is applicable to summer as well? if so... my hypemeter for a F-5 Tornado leveling off a part of NOVA is 7 lol
Member Since: January 31, 2007 Posts: 9 Comments: 2250
44. PalmyraPunishment
7:23 PM GMT on June 04, 2008
your mom buckles down.

hahaha. kidding
Member Since: January 31, 2007 Posts: 9 Comments: 2250
43. MDFirefighter
7:22 PM GMT on June 04, 2008
I wish I wasn't working. I'd be out playing in it lol
Member Since: February 11, 2006 Posts: 1 Comments: 1201
42. Zachary Labe
7:20 PM GMT on June 04, 2008
PalmyraPunishment- Well at least here in Pennsylvania this line is not too impressive. All I am getting is some very heavy rain. NO thunder.

MDFirefighter- From what I am looking at widespread 80mph wind gusts could occur with this line.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
41. MDFirefighter
7:18 PM GMT on June 04, 2008
Time to buckle down!
Member Since: February 11, 2006 Posts: 1 Comments: 1201
40. PalmyraPunishment
7:14 PM GMT on June 04, 2008
im alright blizz -- extremely stoked about the summer weather! normally i don't get excited about summer weather (even though i love thunderstorms), but with the recent tornado outbreak i've started to become intrigued. so i'm here to stay...

currently, im in palmyra (until 5:00) - it's raining and getting darker skies. in carlisle i don't know -- but my roomate told me that the neighbors are talking about the tornado watch and whatnot...

i was let down by last weekend's tornado watch... we barely even got a storm. =(
Member Since: January 31, 2007 Posts: 9 Comments: 2250
39. Zachary Labe
7:12 PM GMT on June 04, 2008
Washington DC towercam...

Member Since: December 14, 2007 Posts: 278 Comments: 15045
38. Zachary Labe
7:06 PM GMT on June 04, 2008
Wow I am shocked, look at this thing...



Member Since: December 14, 2007 Posts: 278 Comments: 15045
37. Zachary Labe
7:05 PM GMT on June 04, 2008
Spetrm- Yep that is a major bow echo. Also looks like embedded tornadoes are possible in it also. Storm velocities from radars show a few couplets.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
36. Spetrm
7:03 PM GMT on June 04, 2008
Large cell headed at DC, that sure is going to cuase some problems.
Member Since: June 9, 2007 Posts: 409 Comments: 9857
35. Zachary Labe
7:00 PM GMT on June 04, 2008
MDFirefighter- That is one of the most intense bow echos I have seen in a long time in the Middle Atlantic.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
34. Zachary Labe
6:59 PM GMT on June 04, 2008
New Tornado Watch...


PENNSYLVANIA COUNTIES INCLUDED ARE

CHESTER DELAWARE PHILADELPHIA



Probability of 2 or more tornadoes
Mod (40%)

Probability of 1 or more strong (F2-F5) tornadoes
Low (20%)

Wind
Probability of 10 or more severe wind events
High (70%)

Probability of 1 or more wind events > 65 knots
Mod (40%)

Hail
Probability of 10 or more severe hail events
Mod (50%)

Probability of 1 or more hailstones > 2 inches
Mod (30%)

Combined Severe Hail/Wind
Probability of 6 or more combined severe hail/wind events
High (>95%)
Member Since: December 14, 2007 Posts: 278 Comments: 15045
33. MDFirefighter
6:54 PM GMT on June 04, 2008


Runnnnn!!!!!!! lol
Member Since: February 11, 2006 Posts: 1 Comments: 1201
32. Zachary Labe
6:54 PM GMT on June 04, 2008
PalmyraPunishment- Lol, How are you? What is it doing there in Carisle?
Member Since: December 14, 2007 Posts: 278 Comments: 15045
31. PalmyraPunishment
6:50 PM GMT on June 04, 2008
it's a twistah! it's a twistah!
Member Since: January 31, 2007 Posts: 9 Comments: 2250
30. MDFirefighter
6:18 PM GMT on June 04, 2008
Tornado vortex on radar in West Virginia
Member Since: February 11, 2006 Posts: 1 Comments: 1201
29. Zachary Labe
6:09 PM GMT on June 04, 2008
SEVERE THUNDERSTORM WARNING
PAC055-057-041830-
/O.NEW.KCTP.SV.W.0019.080604T1747Z-080604T1830Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
147 PM EDT WED JUN 4 2008

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
SOUTHERN FRANKLIN COUNTY IN SOUTH CENTRAL PENNSYLVANIA...
SOUTHERN FULTON COUNTY IN SOUTH CENTRAL PENNSYLVANIA...

* UNTIL 230 PM EDT

* AT 145 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM. THIS STORM WAS LOCATED NEAR NEEDMORE...OR 13
MILES SOUTHEAST OF BREEZEWOOD...AND MOVING EAST AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
MERCERSBURG AND CLAYLICK AROUND 200 PM EDT...
GREENCASTLE AROUND 210 PM EDT...
MARION AND CHAMBERSBURG AROUND 215 PM EDT...
WAYNESBORO AND MONT ALTO AROUND 220 PM EDT...
ROUZERVILLE AROUND 225 PM EDT...

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS.

SEVERE THUNDERSTORMS CONTAIN DAMAGING WINDS 58 MPH OR STRONGER...OR
HAIL THREE QUARTERS OF AN INCH OR LARGER. SEEK SHELTER INSIDE A
STURDY LOCATION NOW.

PLEASE REPORT HAIL...STRONG WINDS OR WIND DAMAGE TO THE NATIONAL
WEATHER SERVICE BY CALLING TOLL FREE...1 8 7 7 6 3 3 6 7 7 2.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM EDT WEDNESDAY EVENING
FOR SOUTH CENTRAL PENNSYLVANIA.

LAT...LON 3975 7824 3995 7820 3993 7748 3991 7748
3991 7747 3981 7747 3980 7747 3972 7747
3972 7804
TIME...MOT...LOC 1747Z 278DEG 42KT 3982 7809
Member Since: December 14, 2007 Posts: 278 Comments: 15045
28. Zachary Labe
4:55 PM GMT on June 04, 2008


PENNSYLVANIA COUNTIES INCLUDED ARE

ADAMS CUMBERLAND FRANKLIN
LANCASTER YORK


Tornadoes
Probability of 2 or more tornadoes
Mod (40%)

Probability of 1 or more strong (F2-F5) tornadoes
Low (20%)

Wind
Probability of 10 or more severe wind events
High (80%)

Probability of 1 or more wind events > 65 knots
Mod (40%)

Hail
Probability of 10 or more severe hail events
High (70%)

Probability of 1 or more hailstones > 2 inches
Mod (30%)

Combined Severe Hail/Wind
Probability of 6 or more combined severe hail/wind events
High (>95%)
Member Since: December 14, 2007 Posts: 278 Comments: 15045
27. MDFirefighter
4:41 PM GMT on June 04, 2008
BRING IT ON BLIZZ!!!!
Member Since: February 11, 2006 Posts: 1 Comments: 1201
26. Zachary Labe
4:28 PM GMT on June 04, 2008
TheRasberryPatch- No I do not think there is a way to avoid my maps when commenting, sorry.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
25. TheRasberryPatch
4:20 PM GMT on June 04, 2008
that is how they explained it Blizz.

looks like some wet weather for the day, huh. i hope we get rain like this once a week during the summer. or at least every 10 days. it sure would be great for the gardens.

is there a way to get to the comment section without going through all the maps?
Member Since: January 26, 2007 Posts: 72 Comments: 6233
24. Zachary Labe
4:10 PM GMT on June 04, 2008
A pretty impressive line of thunderstorms is forming and will strengthen throughout today.



SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1148 AM EDT WED JUN 4 2008

PAZ033-034-041645-
BEDFORD-SOMERSET-
1148 AM EDT WED JUN 4 2008

...STRONG THUNDERSTORMS WITH LOCALLY HEAVY RAIN AND GUSTY WINDS WILL
AFFECT SOMERSET AND SOUTHWESTERN BEDFORD COUNTIES...


AT 1147 AM EDT...THE LEADING EDGE OF A LARGE AREA OF RAIN WITH
EMBEDDED STRONG THUNDERSTORMS WAS LOCATED ALONG A LINE FROM 5 MILES
SOUTH OF IRWIN TO CONNELLSVILLE TO 20 MILES SOUTH OF
CONNELLSVILLE...MOVING EAST AT 45 MPH.

WIND GUSTS AROUND 45 MPH AND PEA-SIZED HAIL ARE POSSIBLE WITH THESE
STORMS. A 30 MINUTE PERIOD OF VERY HEAVY RAIN WILL FALL FROM THESE
STORMS...AND WILL CAUSE WATER TO POND ON ROADS AND QUICKLY FILL
ROADSIDE DITCHES AND SMALL STREAMS. EXPECT FREQUENT...DANGEROUS
LIGHTNING FROM THESE STORMS. DO NOT SEEK SHELTER UNDER TREES WHEN
LIGHTNING THREATENS...MOVE INDOORS WHEN A THUNDERSTORM APPROACHES.

THESE STORMS WILL BE NEAR CONFLUENCE...AND ADDISON AROUND NOON...
SEVEN SPRINGS...MOUNT DAVIS...AND CASSELMAN AROUND 1210 PM...
SALISBURY...AND ROCKWOOD AROUND 1215 PM...SOMERSET...MEYERSDALE AND
AND GARRETT AROUND 1220 PM
Member Since: December 14, 2007 Posts: 278 Comments: 15045
23. Zachary Labe
4:01 PM GMT on June 04, 2008


MESOSCALE DISCUSSION 1199
NWS STORM PREDICTION CENTER NORMAN OK
1051 AM CDT WED JUN 04 2008

AREAS AFFECTED...SRN PA...ERN VA PNHDL...NRN VA...WRN AND CNTRL MD

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 041551Z - 041715Z

A WW TO THE EAST OF TORNADO WW 446 WILL LIKELY BE NEEDED BY 18Z.

WITHIN A BELT OF STRONGER WESTERLIES...LOW AMPLITUDE TROUGHING
CONTINUES TO DEVELOP EAST NORTHEASTWARD OUT OF THE LOWER OHIO
VALLEY. THIS IS OCCURRING IN THE FACE OF BROADER SCALE MID-LEVEL
HEIGHT RISES...DOWNSTREAM OF THE VIGOROUS UPPER TROUGH DIGGING INTO
THE SOUTHWESTERN STATES. BUT...FORCING SHOULD REMAIN SUFFICIENT TO
MAINTAIN CONVECTIVE DEVELOPMENT ALREADY UNDERWAY TO THE WEST OF THE
APPALACHIANS.

A SIGNIFICANT CLUSTER OF STORMS...NOW EVOLVING ACROSS NORTHERN WEST
VIRGINIA...APPEARS LIKELY TO REACH THE ALLEGHENY MOUNTAINS BY AROUND
17Z...BEFORE SPREADING ACROSS AND EAST OF THE HIGHER TERRAIN BETWEEN
17-20Z. A LOW-LEVEL BAROCLINIC ZONE ASSOCIATED WITH PRIOR
CONVECTION...AND THE SYNOPTIC FRONT...MAY PROVIDE THE FOCUS FOR THIS
DEVELOPMENT...ACROSS THE EASTERN WEST VIRGINIA PANHANDLE INTO THE
VICINITY OF THE PENNSYLVANIA/MARYLAND BORDER. WHILE THE PRIMARY
ACTIVITY MAY INITIALLY REMAIN TO THE NORTH OF THE WASHINGTON
D.C./BALTIMORE AREA...MORE ISOLATED STORMS COULD BEGIN TO FORM
ACROSS NORTHERN VIRGINIA AS INHIBITION WEAKENS BY THE PEAK HEATING
HOURS.

MIXED LAYER CAPE INCREASING IN EXCESS OF 2000 J/KG WILL BE
SUPPORTIVE OF STRONG UPDRAFTS. AND...AS A WEAKENING UPPER JET
STREAK /BUT STILL LIKELY GREATER THAN 50 KT AT 500 MB/ OVERSPREADS
THE NORTHERN MID ATLANTIC REGION...DEEP LAYER SHEAR WILL BE STRONG
AND SUPPORTIVE OF ISOLATED SUPERCELLS...IN ADDITION TO AN ORGANIZED
STORMS CLUSTER CAPABLE OF PRODUCING DAMAGING WINDS.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
22. Zachary Labe
3:50 PM GMT on June 04, 2008
TheRasberryPatch- I have never heard that term used before. I know what they mean though. It is a low pressure that runs up along a ridge of high pressure I believe.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
21. TheRasberryPatch
1:52 PM GMT on June 04, 2008
0.68" of rain yesterday evening.
temp and dew pt are the same

i see the weather channel has a new name for the storm system working in the midwest and east coast. they call it a ridge runner.
Member Since: January 26, 2007 Posts: 72 Comments: 6233
20. Zachary Labe
10:17 AM GMT on June 04, 2008
MCS complex now rolling into western Pennsylvania just a little behind schedule.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
19. Zachary Labe
12:53 AM GMT on June 04, 2008
JDinWPA- Thankyou! Should rain off an on the entire night heavy at times. Currently here north of Harrisburg it is thundering with moderate rain.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
18. JDinWPA
12:44 AM GMT on June 04, 2008
Good evening Bliz. Once again you have done a nice job with the blog. Thanks for pulling it all together where I can just go to check out what is happening in the area, especially during potentially severe weather situations.

We've been getting light rain on and off since about 2. Perfect for watering the garden! I'm still planting stuff. The cold of May really threw off my schedule.
17. hurigo
12:38 AM GMT on June 04, 2008
Thanks Blizz, I thought it looked ominous.

Thanks for the reporting. I'm off for the night. Stay safe all.
Member Since: October 9, 2005 Posts: 99 Comments: 6706
16. Zachary Labe
12:34 AM GMT on June 04, 2008
sullivanweather- Lol, been a long day. Thanks for pointing that out. I guess I did not analyze that too closely.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
15. sullivanweather
12:31 AM GMT on June 04, 2008
Blizz,

LOL

Bro check the dates on that PNA chart. They're from Jan-Apr.

For some reason the CPC hasn't updated their charts on the teleconnections page.

You have to go each indicies' respective pages.

Here's the current PNA outlook:


Member Since: March 8, 2007 Posts: 273 Comments: 12612
14. Zachary Labe
12:22 AM GMT on June 04, 2008
hurigo- That is called a hatched zone. That is a zone where there is an even higher risk of organized severe weather. Possibly leading to a PDS watch (Potentially dangerous situation thunderstorm/tornado watch).
Member Since: December 14, 2007 Posts: 278 Comments: 15045
13. hurigo
12:17 AM GMT on June 04, 2008
Sorry, Blizz, I realized after I posted that I hadn't been clear, but by that time I started looking up the hurricane years you mentioned in my blog. I'm referring to the maps that show the hail and wind risks. They show percentage risk, but in some sections there is that added aqua-hyphenated zone.
Member Since: October 9, 2005 Posts: 99 Comments: 6706
12. Zachary Labe
12:12 AM GMT on June 04, 2008
hurigo- Which map?
Member Since: December 14, 2007 Posts: 278 Comments: 15045
11. hurigo
11:55 PM GMT on June 03, 2008
Thanks, Blizz.
I just remembered a question that formed in my mind when I was looking at your maps earlier. I can't figure what those hyphenated aqua-like color symbols on the map mean. HELP?
Member Since: October 9, 2005 Posts: 99 Comments: 6706
10. Zachary Labe
11:38 PM GMT on June 03, 2008
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
735 PM EDT TUE JUN 3 2008

PAZ036-063-064-040000-
ADAMS-CUMBERLAND-FRANKLIN-
735 PM EDT TUE JUN 3 2008

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN FRANKLIN...SOUTHWESTERN
CUMBERLAND AND WEST CENTRAL ADAMS COUNTIES...


AT 734 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING
A STRONG THUNDERSTORM LOCATED OVER GREENCASTLE...MOVING NORTHEAST AT
30 MPH.

WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THIS STORM.

THIS STORM WILL BE NEAR MARION AROUND 745 PM...MONT ALTO AROUND 750
PM...MONT ALTO AROUND 755 PM AND FAYETTEVILLE AROUND 800 PM.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
9. Zachary Labe
11:19 PM GMT on June 03, 2008
Strengthening cell over Franklin County in southcentral, PA...

Member Since: December 14, 2007 Posts: 278 Comments: 15045
8. Zachary Labe
11:00 PM GMT on June 03, 2008
hurigo- Well thankyou for those nice comments. The blogs will continue to role out this summer. Feel free to ask any questions any time.

sullivanweather- O my. Wow have not looked at the PNA in a while. Yes it is headed towards -2. The CPC is also in agreement on the warmer than normal prediction for temperatures.
Member Since: December 14, 2007 Posts: 278 Comments: 15045
7. sullivanweather
10:44 PM GMT on June 03, 2008
Blizz,

Look at the dive the PNA is making.

Seems like we're in for a hot 1st two weeks of June. I'm thinking 3-6 degrees above normal through the 15th.
Member Since: March 8, 2007 Posts: 273 Comments: 12612
6. hurigo
10:40 PM GMT on June 03, 2008
Thank you Blizz, for the time and attention you put into your blog. I find it interesting and useful. I like information on "mid-Atlantic" areas and "the Carolinas," but during hurricane season, I get a little annoyed when the weather people use those broad terms, rather then give us specific information on the threat areas.

I have to tell you that I am slowly, but surely, learning more about (non-tropic) weather and the dynamics of it all. I read every word that you post. Each new blog you put up, I find that, somehow, the information sinks in just a little bit more.

Thank you,
Huri
Member Since: October 9, 2005 Posts: 99 Comments: 6706

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About Blizzard92

Cornell University- Atmospheric Sciences Student; Central PA SKYWARN Storm Spotter; American Meteorological Society Member; PA CoCoRaHS Branch Member

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Linglestown, PA
Elevation: 520 ft
Temperature: 24.2 °F
Dew Point: 15.2 °F
Humidity: 68%
Wind: Calm
Wind Gust: 9.0 mph
Updated: 10:37 AM EST on January 18, 2014

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