Mesoscale Discussion 1541

Issued

Jul 22, 2012, 2:38 PM CDT (19:38 UTC)

Expired

Jul 22, 2012, 5:15 PM CDT

In force

3 hr

Issued by

the Storm Prediction Center

Chance of a watch

20%

The Tallahassee radar (KTLH), 161 km from the middle of the area, began a volume at 19:40 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

778 
ACUS11 KWNS 221939
SWOMCD
SPC MCD 221938
FLZ000-GAZ000-ALZ000-222215-

MESOSCALE DISCUSSION 1541
NWS STORM PREDICTION CENTER NORMAN OK
0238 PM CDT SUN JUL 22 2012

AREAS AFFECTED...CNTRL/NORTH FL...FAR SRN GA...FAR SRN AL

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 221938Z - 222215Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...SCATTERED TO NUMEROUS THUNDERSTORMS WILL IMPACT THE AREA
THROUGH THE AFTERNOON...AND WILL BE ASSOCIATED WITH A THREAT FOR
STRONG WINDS. A THREAT FOR ISOLATED DMGG WIND GUSTS WILL EXIST.
WHILE TRENDS WILL CONTINUE TO BE MONITORED...THE NEED FOR A WW IS
CURRENTLY UNLIKELY.

DISCUSSION...STORMS OVER CNTRL/NRN FL INTO ADJACENT AL/GA WILL
LIKELY EVOLVE IN THREE MAIN REGIMES:

/1/ A SQUALL LINE AT THE LEADING EDGE OF A COLD POOL GENERATED BY A
LARGE MASS OF CONVECTION OVER THE COASTAL/OFFSHORE ATLANTIC WATERS
WILL CONTINUE MOVING WNWWD TO NNWWD. ACCOMPANYING MESOSCALE
CIRCULATIONS WILL LIKELY DRIVE A THREAT FOR GUSTY WINDS AS THE WRN
FLANK OF THE COLD POOL ADVANCES INLAND ACROSS THE FL PENINSULA.
AREAS OF INSOLATION/DIABATIC HEATING LEADING THE CONVECTIVE LINE
HAVE SUPPORTED THE DEVELOPMENT OF MLCAPE OF 2000-3500 J/KG PER
MODIFIED 12Z TAMPA SOUNDING. THIS WILL SUPPORT CONTINUED
FORWARD-PROPAGATION FROM COASTAL SECTIONS EXTENDING FROM AROUND
MELBOURNE TOWARD DAYTONA BEACH ACROSS THE CNTRL FL PENINSULA.
ISOLATED DMGG WIND GUSTS COULD OCCUR WITH THIS ACTIVITY.
HOWEVER...WITH INFLOW BEING SOMEWHAT MITIGATED BY SFC WINDS ORIENTED
PARALLEL TO THE COLD POOL MOTION...AND WITH STRONGER BACKGROUND
LOW/MID-LEVEL FLOW ACCOMPANYING A TROPICAL WAVE DISPLACED FARTHER TO
THE SOUTH /REF. MESOSCALE DISCUSSION 1537/...THE SVR THREAT SHOULD
BE ISOLATED.

/2/ ADDITIONAL...LESS-ORGANIZED CONVECTION LEADING THE SQUALL LINE
WILL CONTINUE MOVING WWD ACROSS THE W-CNTRL FL PENINSULA TOWARD THE
TAMPA AREA. THIS ACTIVITY WILL REMAIN REMOVED FROM ANY STRONGER
STORM-SCALE CIRCULATIONS ACCOMPANYING THE SQUALL LINE...AND FROM
STRONGER LOW/MID-LEVEL FLOW ATTENDANT TO THE TROPICAL WAVE...WITH
AOB 15 KT OF ELY/ENELY LOW/MID-LEVEL FLOW INDICATED PER TAMPA VWP.
HOWEVER...PW VALUES FROM 1.75-2.00 INCHES PER GPS DATA SUGGEST
ENHANCED WATER-LOADING PROCESSES AND THE THREAT FOR STRONG WIND
GUSTS.

/3/ LOWER-COVERAGE CONVECTION DEVELOPING ALONG SEA BREEZE BOUNDARIES
FARTHER NORTH TOWARD THE FL BIG BEND/FL PANHANDLE COULD ALSO POSE A
THREAT FOR STRONG WIND GUSTS. HOWEVER...FORCING FOR ASCENT IN THESE
AREAS WILL KEEP ANY THREAT MAINLY ISOLATED. THIS ACTIVITY MAY
EVENTUALLY REACH ADJACENT PARTS OF AL/GA AS THE SEA BREEZE
BOUNDARIES MOVE INLAND.

..COHEN/HART.. 07/22/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MFL...MLB...TBW...JAX...TAE...MOB...

LAT...LON   27508027 27078095 26988188 27158261 27918292 28618283
            29348328 29908375 30048444 29848515 29958549 30348610
            30428698 31018715 31218604 30868340 29738131 28928058
            27508027

Mesoscale Discussions in Florida, 2012Mesoscale Discussions in Georgia, 2012Mesoscale Discussions in Alabama, 2012Every mesoscale discussion in 2012

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.