July Atlantic hurricane outlook

By: Dr. Jeff Masters , 12:55 PM GMT on July 13, 2012

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It's mid-July, and we have yet to see a named storm form in the Atlantic this month. The computer models are not predicting any development through at least July 20, and if we make it all the way to the end of the month without a named storm forming, it will be the first July since 2009 without a named storm. Since the current active hurricane period began in 1995, 13 of 17 years (76%) have had a named storm form during July. The busiest July occurred in 2005, when five named storms and two major hurricanes formed. These included Hurricane Dennis and Hurricane Emily--the strongest hurricanes ever observed so early in the season. Only eight major hurricanes have formed in July since record keeping began in 1851. As seen in Figure 1, most of the last half of July activity occurs in the Gulf of Mexico and waters off the Southeast U.S. coast. These type of storms form when a cold front moves off the U.S. coast and stalls out, with the old frontal boundary serving as a focal point for development of a tropical disturbance (as happened for Alberto, Beryl, Chris, and Debby in 2012.) There will be at least two cold fronts moving off the U.S. Mid-Atlantic coast over the next two weeks. The first of these fronts will push offshore around July 20, and we will need to watch the waters offshore of North Carolina for development then. Formation potential will be aided by ocean temperatures that are about 0.7°C (1°F) above average along the U.S. East Coast.


Figure 1. Tracks of all tropical storms and hurricanes 1851 - 2006 that formed July 16-31. The U.S. coast from North to Texas are the preferred strike locations. Only a few storms have formed in the tropical Atlantic and Caribbean in July. Wind shear is typically too high and SSTs too cool in July to allow African waves in the Caribbean and tropical Atlantic to develop into tropical storms. However, a few long-track "Cape Verdes" hurricanes have occurred in July, spawned by tropical waves that came off the coast of Africa. African tropical waves serve as the instigators of about 85% of all major hurricanes.


Figure 2. The seasonal distribution of Atlantic hurricane activity shows that July typically has low activity. Image credit: NHC.

Sea Surface Temperatures: slightly above average
The departure of Sea Surface Temperatures (SST) from average over the tropical Atlantic between Africa and Central America was about 0.3°C above average during June (Figure 3.) This figure has not changed much over the first two weeks of July. These temperatures are not warm enough to appreciably affect the odds of a July named storm or hurricane. The strength of the Azores-Bermuda high has been near average over the past two weeks, driving near-average trade winds. The latest 2-week run of the GFS model predicts continued average-strength trade winds through late-July, so SSTs should remain about 0.3°C above average during this period, due to average amounts of cold water mixing up from below due to the wind action on the water.


Figure 3. Sea Surface Temperature (SST) departure from average for July 12, 2012. SSTs were 0.3°C above average over the tropical Atlantic's Main Development region for hurricanes, from Africa to Central America between 10° and 20° North Latitude. Note the large region of above average SSTs along the Equatorial Pacific off the coast of South America, the hallmark of a developing El Niño episode. Image credit: NOAA/NESDIS

El Niño on the way?
For two consecutive weeks, ocean temperatures 0.5 - 0.6°C above average have been present in the tropical Eastern Pacific, which is right at the threshold for a weak El Niño episode. NOAA's Climate Prediction Center has issued an El Niño Watch, and gives a 61% chance that El Niño conditions will be present during the August - September - October peak of the Atlantic hurricane season. The likely development of a full-fledged El Niño episode means that Atlantic hurricane activity will probably be suppressed in 2012, due to the strong upper-level winds and high wind shear these events typically bring to the tropical Atlantic.


Figure 4. Sea Surface Temperature (SST) departure from average for the the equatorial Eastern Pacific (the area 5°N - 5°S, 120°W - 170°W, also called the "Niña 3.4 region"). El Niño conditions exist when the SST in this region rises 0.5°C above average. As of July 9, 2012, SSTs in the Niño 3.4 region had risen to 0.5°C above average. To be considered an "El Niño episode", El Niño conditions must occur for five consecutive months, using 3-month averages. Image credit: NOAA Climate Prediction Center.

Wind shear: above average
Wind shear is usually defined as the difference in wind between 200 mb (roughly 40,000 foot altitude) and 850 mb (roughly 5,000 foot altitude). In most circumstances, wind shear above 20 knots will act to inhibit tropical storm formation. Wind shear below 12 knots is very conducive for tropical storm formation. High wind shear acts to tear a storm apart. The jet stream has two bands of strong high-altitude winds that are currently bringing high wind shear to the Atlantic. The southern branch (subtropical jet stream) is bringing high wind shear to the Caribbean, and the northern branch (polar jet stream) is bringing high wind shear to the waters offshore of New England. This configuration often leaves a "hole" of low shear between the two branches, off the Southeast U.S. coast and over the Gulf of Mexico. The jet stream is forecast to maintain this two-branch pattern over the coming two weeks. Wind shear has been about 10 - 20% higher than average over the first two weeks of July, and is predicted to be mostly above average for the coming two weeks. This will cut down on the odds of a July storm.


Figure 5. Vertical instability over the Caribbean Sea in 2012 (blue line) compared to average (black line.) The instability is plotted in °C, as a difference in temperature from near the surface to the upper atmosphere. Thunderstorms grow much more readily when vertical instability is high. Instability has been lower than average, due to an unusual amount of dry air in the atmosphere, reducing the potential for tropical storm formation. Image credit: NOAA/NESDIS/CIRA.

Dry air: above average
As seen in Figure 5, there has been an unusual amount of dry, stable air in the Caribbean this year creating low levels of vertical instability. This has occurred due to a combination of dry air from Africa, and upper-atmosphere dynamics creating large areas of sinking air that dry as they warm and approach the surface. The Gulf of Mexico and tropical Atlantic between the coast of Africa and the Lesser Antilles have also seen low vertical instability this summer. June and July are the peak months for dry air and dust coming off the coast of Africa, and the Saharan dust storms have been quite active over the past two weeks. Expect dry air to be a major deterrent to any storms that try to form in the tropical Atlantic during July.

Steering currents: average
The predicted steering current pattern for the next two weeks is a typical one for July. We have an active jet stream bringing many troughs of low pressure off the East Coast of the U.S. These troughs are frequent enough and strong enough to recurve any tropical storms or hurricanes that might penetrate north of the Caribbean Sea. Steering current patterns are predictable only about 3 - 5 days in the future, although we can make very general forecasts about the pattern as much as two weeks in advance. There is no telling what might happen during the peak months of August, September, and October--we might be in for a repeat of the favorable 2010 and 2011 steering current pattern, which recurved most storms out to sea--or the unfavorable 2008 pattern, which steered Ike and Gustav into the Gulf of Mexico.

Summary: a below average chance of a July tropical storm
Given that none of the computer models are forecasting tropical storm formation in the coming seven days, SSTs are only slightly above average, and wind shear and vertical stability are above average, I'll go with a 30% chance of a named storm forming in the Atlantic during the remainder of July.


Figure 6. Hurricane Emilia over the Eastern Pacific at 20:35 UTC July 10, 2012. At the time, Emilia was a Category 3 hurricane with 125 mph winds. Emilia peaked earlier in the day as a Category 4 storm with 140 mph winds--the strongest hurricane in the East Pacific so far in 2012. Image credit: NASA.

An active Eastern Pacific hurricane season
It's been a very active start to the Eastern Pacific hurricane season, where we've already had six named storms, four hurricanes, and three intense hurricanes. A typical season has 4 named storms, 2 hurricanes, and 0 intense hurricanes by July 14. The formation of Tropical Storm Fabio on July 12 marks the 4th earliest formation of the Eastern Pacific's season's sixth storm. The record is held by the year 1985, when the season's sixth storm formed on July 2. Record keeping began in 1949.

Have a great weekend, everyone, and I'll be back Monday with a new post.

Jeff Masters

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Convection almost fully around the eye now.
Member Since: March 16, 2012 Posts: 127 Comments: 7940


RIP Stallone's son Sage....





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1109. Patrap
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1108. Grothar
Quoting bappit:

Narcissism can be ugly.


How many narcissists does it take to change a light bulb?. One, he holds it and the world revolves around him.
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1107. hydrus
Quoting wxchaser97:
Wasn't alive for anyone of them, but looking at the storms it had to be boring.
72 and 94 were interesting .Gettin sloppy around here..
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1106. Patrap
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Member Since: March 16, 2012 Posts: 127 Comments: 7940
Quoting MontanaZephyr:
oooo...

Just had a pop-up commercial with audio!

Took me a minute t find where the gxd dxmned thing was coming from.

This site!

Some Gxd Dxmned Shxt about about buy some drugs.

I see the weather channel deal has already fuqed the site.

What a god dxmned drag.


those have been there from time to time, before TWC.
Member Since: February 11, 2012 Posts: 0 Comments: 9725
Derived from the 14July12amGMT (NHC) ATCF data for TropicalStormEmilia:
Its vector had changed from 15.5mph(25km/h) West to 14.4mph(23.2km/h) West
MaxSusWinds had held steady at 45knots(52mph)83km/h
And minimum pressure decreased from 998millibars to 997millibars

For those who like to visually track TS.Emilia's path...
HPV is Hanalei,Kauai :: HNL is Honolulu,Oahu :: OGG is Kahalui,Maui :: ITO is Hilo,Hawaii

Easternmost dot on the connected line-segments is where Emilia became a TropicalStorm again
Easternmost dot on the longest line is TS.Emilia's most recent position

The longest line is a straightline projection through TS.Emilias's 2 most recent positions to its closest approach to Hawaii's coastline. (All 4 of the endpoints below are on the same blob)
13July6pmGMT: TS.Emilia had been headed toward passing 364miles(586kilometres) South of Hawaii
14July12amGMT: TS.Emilia had been headed toward passing 353miles(568kilometres)South of Hawaii
14July6amGMT: TS.Emilia had been headed toward passing 343miles(552kilometres) South of Hawaii
14July12pmGMT: TS.Emilia was heading toward passing 332miles(534kilometres) South of Hawaii
in ~4days11hours from now

Copy&paste hpv, hnl, 13.665n154.97w, 13.818n155.018w, 13.96n155.063w, ogg, ito, 15.3n124.2w-15.5n125.4w, 15.5n125.4w-15.5n126.7w, 15.5n126.7w-15.5n127.9w, 15.5n127.9w-15.5n129.3w, 15.5n129.3w-15.5n130.6w, 15.5n129.3w-14.114n155.112w, 18.911n155.681w-14.114n155.112w into the GreatCircleMapper for more information
The previous mapping for comparison
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Member Since: March 16, 2012 Posts: 127 Comments: 7940
Quoting wxmod:
Soot on the arctic ice cap is caused by Russian forest fires. The soot will melt the ice faster in a key shipping lane and allow oil exploration to be conducted off shore in the arctic ocean.



Fantastic!

...
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1100. Grothar
Quoting Tropicsweatherpr:


Yes,that ULL needs to go away to turns things more favorable. Thank you for the brief take on it.



I see you corrected the spelling of the ULL. :) Didn't want to mention it. LOL
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Right now is very difficult, to a low pressure develop because the wind shear is present in the atlantic.



the forecast is maintain the wind shear, will continue because some jet stream that probably stay crossing the atlantic nearly 6 to 7 days.

so july for my is dead in tropical cyclone formation.

El enso is in neutral phase and for me el nino could develops but in mid octuber.

so the season will have some favorebles paterns.

I stay with 13 to 14 tropical storm
4 to 6 huricanes
2 to 3 majors

Member Since: June 20, 2012 Posts: 0 Comments: 2157
Quoting sporteguy03:

It will happen don't worry you'll get your hurricanes soon enough.

I know it will happen, it always happens.
Member Since: March 16, 2012 Posts: 127 Comments: 7940
Quoting wxmod:
Soot on the arctic ice cap is caused by Russian forest fires. The soot will melt the ice faster in a key shipping lane and allow oil exploration to be conducted off shore in the arctic ocean.



oh boy!!!!!!!!!!!! hip hip hooray!!!!!!!
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Quoting wxchaser97:

A CV storm would be nice so some people would stop saying the season is a bust, if anyone is saying that.

It will happen don't worry you'll get your hurricanes soon enough.
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Member Since: March 16, 2012 Posts: 127 Comments: 7940
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Member Since: March 16, 2012 Posts: 127 Comments: 7940
Quoting bappit:

That was 2011. Did the GFDL impress anyone last year?



I think not....looking at more data.
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1091. wxmod
Soot on the arctic ice cap is caused by Russian forest fires. The soot will melt the ice faster in a key shipping lane and allow oil exploration to be conducted off shore in the arctic ocean.

Member Since: October 4, 2011 Posts: 0 Comments: 1752
Early stages and characteristics of El Nino:

Although its causes are still being investigated, El Nino events begin when trade winds, part of the Walker circulation, falter for many months. A series of Kelvin waves relatively warm subsurface waves of water a few centimetres high and hundreds of kilometres wide across the Pacific along the equator and create a pool of warm water near South America, where ocean temperatures are normally cold due to upwelling. The weakening of the winds can also create twin cyclones, another sign of a future El Nino.[8] The Pacific Ocean is a heat reservoir that drives global wind patterns, and the resulting change in its temperature alters weather on a global scale.[9] Rainfall shifts from the western Pacific toward the Americas, while Indonesia and India become drier.[10]

Jacob Bjerknes in 1969 contributed to an understanding of ENSO by suggesting that an anomalously warm spot in the eastern Pacific can weaken the east-west temperature difference, disrupting trade winds that push warm water to the west. The result is increasingly warm water toward the east.

Link
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1089. wxmod
petawatt-million billion watts-laser

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Quoting GTcooliebai:
Currently with the way the High is situated we may have some long track Cape-Verde Storms. Our saving grace will have to be the SAL which is holding pretty strong at the moment.
Yeah but it's even worse when they start to develop near the caribbean and the U.S because people have less warning time.
Member Since: August 14, 2010 Posts: 10 Comments: 16803
Quoting washingtonian115:
Yep.Watch the gulf this year.May have a few surprises down the road.
Currently with the way the High is situated we may have some long track Cape-Verde Storms. Our saving grace will have to be the SAL which is holding pretty strong at the moment.
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Definitely a small, but not exactly pinhole, eye...

Member Since: February 11, 2012 Posts: 83 Comments: 7736
Quoting WxGeekVA:



lol and PINHOLE eye!!
Member Since: March 16, 2012 Posts: 127 Comments: 7940
Quoting bappit:

Narcissism can be ugly.
Yeah.But this just takes the cake right here.I'd take his ego over that any day.
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1083. wxmod
Monster fires in Russia are incinerating huge forest areas. There are new fires popping up every single day. Likely that they are arson caused and are rapidly spreading because of untreated logging debris.


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Quoting wxchaser97:


Member Since: September 3, 2011 Posts: 13 Comments: 3470
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1080. bappit
Quoting washingtonian115:
My eye vision is all ready horrible and now I've gone blind!!

Narcissism can be ugly.
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Quoting WxGeekVA:
Meanwhile, in Joe B. Land...

My eye vision is all ready horrible and now I've gone blind!!
Member Since: August 14, 2010 Posts: 10 Comments: 16803
1077. bappit
Quoting washingtonian115:
I think what he meant was that if no hurricanes/T.C form at all then the atmosphere will be unstable.Yes its very sad that hurricanes bring death and destruction,but they do bring hot air from out of the tropics and transport them to the poles.If no hurricanes form you could have something way worse.

That process occurs whether we have TC's or not. Since TC's are infrequent at best, the 24 x 7 events do the job.
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Quoting WxGeekVA:
As we sit here waiting for a storm in the Atlantic to track....



.......can't help but wonder how much longer we have to wait. This is nerve racking!

Good morning all from sunny Antigua and Barbuda
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While we're waiting for space storms and hurricanes to materialize, here is a queston for one of you physics types:

Suppose you could drill a hole all the way to center of the earth... oh, say, a meter in diameter.

At what depth would the air pressure be sufficient to cause the air to behave as a liquid...? What would the air temperature be (approximately, of course) ...?

I assume at some depth, people would 'float' and move about like sea creatures, if the temperature were not objectionable.
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Quoting WxGeekVA:


Wow! Almost the entire Lower 48 has a chance of storms today!
The entire lower 48 needs the rain as well!
Member Since: March 16, 2012 Posts: 127 Comments: 7940
Meanwhile, in Joe B. Land...

I made it stop!
Member Since: September 3, 2011 Posts: 13 Comments: 3470
Quoting GTcooliebai:
I was noticing that yesterday. Along the west coast of FL. we have been receiving rain everyday for the past week and more is on the way for next week. I would think this wetness would be considered a pattern as the dry air that was in the Gulf last year is no longer there this year and we saw only one storm develop in the Gulf, this year we've had Debby so far and we're only a month and half in to the Hurricane Season with Aug. Sep. Oct. and Nov. still to come. A bit of foreshadowing?
Yep.Watch the gulf this year.May have a few surprises down the road.
Member Since: August 14, 2010 Posts: 10 Comments: 16803
1071. LargoFl
be a bit careful outdoors new jersey folks.....................EXCESSIVE HEAT WATCH IN EFFECT FROM MONDAY AFTERNOON THROUGH
WEDNESDAY EVENING...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED AN
EXCESSIVE HEAT WATCH...WHICH IS IN EFFECT FROM MONDAY AFTERNOON
THROUGH WEDNESDAY EVENING.

* HEAT INDEX VALUES...AROUND 102 DEGREES MONDAY AFTERNOON...RESULTING
FROM TEMPERATURES NEAR 95 DEGREES AND DEW POINTS NEAR 70. HEAT
INDEX VALUES ARE EXPECTED TO RANGE BETWEEN 100 AND 105 DEGREES
TUESDAY AND WEDNESDAY AFTERNOON. OVERNIGHT LOWS MONDAY NIGHT AND
TUESDAY NIGHT MAY NOT DROP LOWER THAN THE UPPER 70S IN THE
HIGHLY URBANIZED AREAS.

* TIMING...THE EXCESSIVE HEAT IS EXPECTED TO START MONDAY
AFTERNOON... WITH THE HIGHEST HEAT INDEX VALUES TUESDAY AND
WEDNESDAY AFTERNOON.

* IMPACTS...THE CUMULATIVE IMPACTS OF THE HEAT ARE A DANGER
ESPECIALLY FOR THE ELDERLY...INFIRM...THE VERY YOUNG...AND
THOSE IN INNER CITY AREAS THAT DO NOT HAVE AIR CONDITIONING.
PETS ALSO ARE SUSCEPTIBLE TO THE HEAT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

AN EXCESSIVE HEAT WATCH MEANS THAT A PROLONGED PERIOD OF HOT
TEMPERATURES IS EXPECTED. THE COMBINATION OF HOT TEMPERATURES AND
HIGH HUMIDITY WILL COMBINE TO CREATE A DANGEROUS SITUATION IN
WHICH HEAT ILLNESSES ARE POSSIBLE. DRINK PLENTY OF FLUIDS...STAY
IN AN AIR-CONDITIONED ROOM...STAY OUT OF THE SUN...AND CHECK UP
ON RELATIVES AND NEIGHBORS.
Member Since: August 6, 2011 Posts: 4 Comments: 38063
Member Since: August 9, 2009 Posts: 10 Comments: 4940
Quoting wxchaser97:
...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NRN GRT BASIN
AND NRN RCKYS...

...SYNOPSIS...
A TROUGH-RIDGE-TROUGH-RIDGE PATTERN WILL PREVAIL FROM W-TO-E ACROSS
THE LWR 48 THIS PERIOD...WELL S OF THE MAIN BELT OF THE WLYS THAT
WILL REMAIN OVER CNTRL CANADA. THE MOST SIGNIFICANT PART OF THE
ABOVE PATTERN AS FAR AS SVR TSTM POTENTIAL IS CONCERNED IS THE UPR
LOW NOW OVER NW ORE. THE LOW SHOULD EDGE E/SE INTO CNTRL ORE
TODAY...BEFORE TURNING NE TOWARD WRN ID EARLY SUN AS UPSTREAM
DISTURBANCE NOW APPROACHING THE BC CST CONTINUES SE TO VANCOUVER
ISLAND. OTHERWISE...OVERALL PATTERN WILL REMAIN LARGELY
STATIC...WITH ONLY SLOW EWD MOVEMENT EXPECTED WITH TROUGH NOW OVER
THE UPR MS VLY.


Wow! Almost the entire Lower 48 has a chance of storms today!
Member Since: September 3, 2011 Posts: 13 Comments: 3470
Quoting washingtonian115:
Oh?.I just found out something that could be bad and good.About a week or two before Irene Affected N.Y,N.Y.C had an all time record of rain for a day...The gulf coast has been very wet....And it seems that nature is foreshadowing with the Gulf having low shear and plenty of moisture.Remember the east coast last year was where about a handful of storms got going...it was like the sweet spot....
I was noticing that yesterday. Along the west coast of FL. we have been receiving rain everyday for the past week and more is on the way for next week. I would think this wetness would be considered a pattern as the dry air that was in the Gulf last year is no longer there this year and we saw only one storm develop in the Gulf, this year we've had Debby so far and we're only a month and half in to the Hurricane Season with Aug. Sep. Oct. and Nov. still to come. A bit of foreshadowing?
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1067. bappit
Quoting HurricaneHunterJoe:
Subject: GFDL Hurricane Prediction System Changes:
Effective May 17, 2011

Effective Tuesday, May 17, 2011, beginning with the 1200
Coordinated Universal Time (UTC) run, the National Centers
for Environmental Prediction (NCEP) will upgrade the
Geophysical Fluid Dynamics Laboratory (GFDL) Hurricane
Prediction System. The scientific changes to the model
include the following:

- Upgrade Simplified Arakawa-Schubert (SAS) deep convection
parameterization to new version implemented in the NCEP
Global Forecast System (GFS)
- Modify the surface enthalpy exchange coefficient and
dissipative heating effect
- Expand coupled region in the Eastern Atlantic domain
to prevent storms from losing coupling effect with the
ocean due to insufficient overlap with the Western Atlantic
region. The new overlap will be 25 degrees.
- Correct several bugs in the model.

In testing, these improvements resulted in an average reduction
of forecast error of about 20 percent in the Atlantic basin
for the 3 to 5 day forecast period for tests of storms from
the 2010 Atlantic hurricane season.

That was 2011. Did the GFDL impress anyone last year?
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1066. LargoFl
FLOOD WATCH
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1144 AM EDT SAT JUL 14 2012

VAZ025>031-036>040-503-504-WVZ050-055-501>506-142 345-
/O.NEW.KLWX.FF.A.0005.120714T1600Z-120715T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000 Z.OO/
AUGUSTA-ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE-
NELSON-ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-WEST ERN HIGHLAND-
EASTERN HIGHLAND-HAMPSHIRE-HARDY-WESTERN GRANT-EASTERN GRANT-
WESTERN MINERAL-EASTERN MINERAL-WESTERN PENDLETON-
EASTERN PENDLETON-
INCLUDING THE CITIES OF...STAUNTON...WAYNESBORO...HARRISONBURG...
WINCHESTER...FRONT ROYAL...CHARLOTTESVILLE...WASHINGTON...
HIGHTOWN...MONTEREY...MOOREFIELD...BAYARD...MOUNT STORM...
PETERSBURG...ELK GARDEN...KEYSER...FORT ASHBY...CIRCLEVILLE...
FRANKLIN
1144 AM EDT SAT JUL 14 2012

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF THE CENTRAL AND NORTHERN
SHENANDOAH VALLEY...THE POTOMAC HIGHLANDS AND CENTRAL FOOTHILLS.

* THROUGH THIS EVENING

* NUMEROUS SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON
AND CONTINUE INTO THE EVENING. LOCALLY HEAVY DOWNPOURS WITH
THESE STORMS MAY PRODUCE RAINFALL AMOUNTS OF TWO INCHES IN LESS
THAN ONE HOUR.

* EXCESSIVE RAINFALL FROM THESE STORMS COULD CAUSE CREEKS AND
STREAMS TO RISE QUICKLY OUT OF THEIR BANKS...AS WELL AS FLOODING
OF LOW- LYING AREAS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&
Member Since: August 6, 2011 Posts: 4 Comments: 38063
...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NRN GRT BASIN
AND NRN RCKYS...

...SYNOPSIS...
A TROUGH-RIDGE-TROUGH-RIDGE PATTERN WILL PREVAIL FROM W-TO-E ACROSS
THE LWR 48 THIS PERIOD...WELL S OF THE MAIN BELT OF THE WLYS THAT
WILL REMAIN OVER CNTRL CANADA. THE MOST SIGNIFICANT PART OF THE
ABOVE PATTERN AS FAR AS SVR TSTM POTENTIAL IS CONCERNED IS THE UPR
LOW NOW OVER NW ORE. THE LOW SHOULD EDGE E/SE INTO CNTRL ORE
TODAY...BEFORE TURNING NE TOWARD WRN ID EARLY SUN AS UPSTREAM
DISTURBANCE NOW APPROACHING THE BC CST CONTINUES SE TO VANCOUVER
ISLAND. OTHERWISE...OVERALL PATTERN WILL REMAIN LARGELY
STATIC...WITH ONLY SLOW EWD MOVEMENT EXPECTED WITH TROUGH NOW OVER
THE UPR MS VLY.
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Member Since: September 3, 2011 Posts: 13 Comments: 3470
1063. LargoFl
.NOW...
SCATTERED SHOWERS AND FEW THUNDERSTORMS WILL MOVE RAPIDLY WEST AT
20 MPH ACROSS THE ATLANTIC WATERS AND ONSHORE OF THE EAST COAST
METRO REGION. ADDITIONAL STORMS WILL THEN DEVELOP INLAND AND
CONTINUE WEST ALSO PASSING OVER LAKE OKEECHOBEE. A FEW LIGHTNING
STRIKES WILL BE POSSIBLE ALONG WITH A BRIEF HEAVY DOWNPOUR.
RAINFALL AMOUNTS WILL BE LIMITED TO LESS THAN A QUARTER OF AN
INCH.
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Member Since: March 16, 2012 Posts: 127 Comments: 7940
1061. LargoFl
Member Since: August 6, 2011 Posts: 4 Comments: 38063

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.