Friday, November 23, 2007

Thanksgiving weekend weather update

I hope you had a great Thanksgiving yesterday. It was a great day for me as I was spending time with my children and my parents. We should always give thanks but I want to take a moment here to thank God for my family. I am so fortunate to have three great sons, a great sister (who lives far away and was taking food to eldely shut-ins), and both parents who are still alive and kicking. My mom made a wonderful meal for us yesterday with all of the trimmings. I hope you have (or will) take a few moments to give thanks.

Thanksgiving was not the best of days for some Santa Rosa County Florida residents who were struck by a possible tornado. The good news was that despite the damage there were no injuries reported.
Aricle from Orlando Sentinel. This is just a reminder that we remain in a severe weather season here in the Deep South.

Speaking of severe weather, there is still a pretty good chance of that occurring Sunday night or Monday. Here are a few excerpts from weather sources I trust:


James Spann at Alabamawx.com:
"A severe weather threat still seems likely late Sunday night into Monday as we break into the warm sector of the storm system. The primary window for severe storms seems to be in the general period from midnight Sunday night through noon on Monday. At midday Monday, the cold front should extend southward, roughly along I-65, from a surface low over western Kentucky. While the synoptic scale features look favorable for severe weather, the mesoscale is the key to the magnitude of the event, and we really won’t know that until Sunday. We all need to keep an eye on this."

NWS Birmingham
"AS THIS IMPULSE MOVES OUT OF CENTRAL ALABAMA BY SUNDAY
MORNING...MUCH ADVERTISED FRONTAL SYSTEM WILL BEGIN TO
FORM IN WESTERN GULF...WITH SURFACE LOW MOVING
NORTHEAST IN WESTERN TENNESSEE...AND SURFACE FRONT
MOVING THROUGH CENTRAL ALABAMA BY 12Z MONDAY.
SURFACE LOW WILL BE JOINED WITH IMPRESSIVE LOW LEVEL JET
DYNAMICS...UPPER SUPPORT...AND WARM SECTOR AT LEAST
ACROSS SOUTHERN AREAS. THIS COULD ALL RESULT IN THE
DEVELOPMENT OF A ROUND OF SEVERETHUNDERSTORMS
SUNDAY NIGHT INTO MONDAY...WITH DEWPOINTS IN THE
MID 60S ACROSS MUCH OF AREA. HIGHS SUNDAY IN THE 60S
WITH LOWS SUNDAY NIGHT IN THE MID 50S NORTHWEST TO
LOWER 60S SOUTHEAST. TIMING WILL BE NEED TO BE
WATCHED CLOSELY AS WE MOVE TOWARD THE WEEKEND
AND WILL CONTINUE TO BE HIGHLIGHTED IN THE HAZARDOUS
WEATHEROUTLOOK. THE COLD FRONT SHOULD EVENTUALLY
EXIT THE AREA BY18Z ON MONDAY."

NWS Huntsville
"THE GFS DURING MONDAY CONTINUED TO DEPICT A
NEGATIVELY TILTED UPPER TROUGH AS THIS SYSTEM MOVE
TO THE NORTH AND EAST. GFS SHOWALTER INDICES WERE
ZERO TO -2C DURINGTHE OVERNIGHT HOURS...WITH HIGH
0-3KM HELICITIES PER THE NAM. TIMINGAT THIS TIME IS
DURING SUNDAY NIGHT AND MONDAY MORNING...WHICH
COULDHELP REDUCE STRONG/SEVERE STORM CHANCES.
MODEL AND HPC QPF SUGGESTANOTHER 1-3 INCHES OF RAIN
IS POSSIBLE THROUGH MONDAY."

NWS Jackson, MS
"SIGNIFICANT SEVERE WEATHER AND HEAVY RAIN EVENT
STILL ON TAP FOR SUNDAY AND SUNDAY NIGHT...IT
CONTINUES TO LOOK MORE LIKELY THAT SEVERE WEATHER
AND HEAVY RAINFALL WILL DEVELOP OVER THE FORECAST
AREA SUNDAY AND PERSIST THROUGH SUNDAY NIGHT. THE
POTENTIAL FOR HEAVY RAINFALL EXISTS OVER THE ENTIRE
AREA...WHILE THE GREATEST POTENTIAL FOR SEVERE
THUNDERSTORMS IS ALONG AND SOUTHEAST OF THE NATCHEZ
TRACE PARKWAY.WE ARE MORE CONFIDENT NOW WITH THESE
AREAL DESIGNATIONS...BUT SEVERE WEATHER STILL CANNOT
BE RULED OUT OVER THE ENTIRE AREA. THE 00Z OPERATIONAL
GFS/ECMWF/GFS ENSEMBLE AND 06Z GFS ARE IN GOOD
AGREEMENT ON THE TIMING AND PLACEMENT OF THE SURFACE
LOW CIRCULATION...TRACKING IT NEWD ALONG THE NATCHEZ
TRACE SUNDAY NIGHT.THIS IS IN AGREEMENT WITH PREVIOUS
FORECAST THINKING AND SEE NO REASON TO DEVIATE FROM
IT AT THIS POINT. AS THE PRIMARY SHORTWAVE TROUGH
APPROACHES SUNDAY...SOUTHERLY LOW-LEVEL FLOW AND
MOISTURE TRANSPORT WILL INCREASE DRAMATICALLY
(850MB FROM 20KT TO 50KT AND850MB THETAE FROM ~320
TO 330+ DEG K) UNDERNEATH RIGHT ENTRANCE REGION OF
A 120KT UPPER JET. ELEVATED INSTABILITY SUNDAY MORNING
(SHOWALTER INDICES ~ -2 DEG C) WILL GRADUALLY
TRANSITION TOSFC-BASED INSTABILITY AS THE WARM
SECTOR SURGES NORTHWARD (BL LI -2TO -3 DEG C) ACROSS
SRN AND ERN MS. WIDESPREAD DEEP CONVECTION SHOULD
DEVELOP BY SUNDAY AFTERNOON ACROSS MUCH OF THE
AREA. THERE MAY BE A SMALL WINDOW FOR DISCRETE SFC-
BASED TSTMS SUNDAY AFTERNOON IN THE HBG-LAUREL
AREA AS ENVIRONMENTAL SHEAR BECOMES VERYIMPRESSIVE
(0-1KM 35-40KTS, 0-6KM ~45KTS). HOWEVER...EXPECT THE
PRIMARY CONVECTIVE MODE WILL BECOME ORGANIZED
AND LINEAR. WHILE 2-8KM SHEAR VECTORS ARE FORECAST
TO BE NORMAL TO THE APPROACHING COLD FRONT
SUGGESTING CELLULAR CONVECTION...THEY ARE ALSO
FORECAST TO BE QUITE WEAK (<>
STRONG FORCING AND LOW-LEVELCONVERGENCE IMPLIES
THE DEVELOPMENT OF A LINEAR CONVECTIVE SYSTEM
COMPRISED OF OCCASIONAL BOWS AND LEWPS AND ISOLATED
TORNADOES. GIVEN THE STRENGTH OF THE LOW-LEVEL WIND
FIELDS...EXPECT THAT SIGNIFICANT WIND DAMAGE COULD
OCCUR OVER PORTIONS OF CNTRL/ERN MS WITH THE
GREATEST RISK BEING ALONG THE INTERSTATE 59 CORRIDOR
FORM HBG TO MEI...AND SLIGHTLY LOWER RISK NEAR AND
SOUTHEAST OF THE NATCHEZ TRACE. THE PAST FEW RUNS
OF THE GFS HAVE BEEN CONSISTENT IN THIS PORTRAYAL."

Mobile NWS:
"THE WARM FRONT WILL MOVE ONSHORE SUNDAY AS THE
LONG ANTICIPATED GULF LOW STARTS TO GEN UP TO THE
WEST. THE LATEST GFS AND ECMWF PACKAGES ARE IN FAIR
AGREEMENT GENNING UP A SURFACE LOW SOUTH OF LAKE
CHARLES AS THE STRONG SHORTWAVE TRACKS EAST OVER
CENTRAL TEXAS. THE SURFACE LOW MOVES NORTHEAST
ACROSS MISSISSIPPI THROUGH SUNDAY NIGHT AS THE
SHORTWAVE GOES NEGATIVE TILT OVER EASTERN TEXAS...
AND A STRONG 850 MB LOW LEVEL JET (40-60 KTS) TRANSLATES
SLOWLY EASTWARD ACROSS MISSISSIPPI AND ALABAMA. THIS
RESULTS IN A SUBSTANTIALLY INCREASED WIND SHEAR
PATTERN WITH HELICITY VALUES (0-3 KM) RANGING FROM 300
TO 500 ACROSS OUR AREA LATE SUNDAY INTO EARLY MONDAY.
THERE APPEARS TO BE SUFFICIENT INSTABILITY TO REALIZE
STRONGLY ROTATING/SUSTAINED UPDRAFTS...SO THE FORECAST
PATTERN CONTINUES TO INDICATE (FOR SEVERAL MODEL RUNS
NOW) A DISTINCT POSSIBILITY THAT WE COULD SEE A SIGNIFICANT
SEVERE WEATHER OUTBREAK ACROSS THE CENTRAL GULF
COAST REGION LATE SUNDAY THROUGH EARLY MONDAY."

Before I go I stumbled across a book review for a book I am really interested in entitled F5. It is the story of how an Alabama community (Athens) was affected by the Superoutbreak in 1974. Who knows, maybe I will get it for Christmas.

2 comments:

Rick said...

Looks like we aren't in for much but rain down here. We will take it. When did you get the 3D anylist??

Mike said...

I haven't gotten it. I just got the image from somewhere else.

I don't know. I think you have a better chance of severe wx than us Sun night/mon...