Mesoscale Discussion 263

Issued

Mar 17, 2003, 1:57 PM EST (18:57 UTC)

Expired

Mar 17, 2003, 4:00 PM EST

In force

2 hr

Issued by

the Storm Prediction Center

The Tampa radar (KTBW), 114 km from the middle of the area, began a volume at 18:59 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

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829 
ACUS11 KWNS 171857
SWOMCD
SPC MCD 171857 
FLZ000-172100-

MESOSCALE DISCUSSION 0263
NWS STORM PREDICTION CENTER NORMAN OK
1257 PM CST MON MAR 17 2003

AREAS AFFECTED...WRN FL PENINSULA / ERN PANHANDLE / NRN FL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 171857Z - 172100Z

EXPECT A GRADUAL INCREASE IN CONVECTION OVER THE NEXT SEVERAL
HOURS FROM THE ERN FL PANHANDLE...NORTH FLORIDA REGION SWD THRU
THE WRN HALF OF THE FL PENINSULA. HOWEVER...A WW IN NOT
ANTICIPATED.



RECENT IR/WV IMAGERY DEPICT TWO CONVECTIVE CLUSTERS...ONE IN THE
ERN PANHANDLE REGION AND ANOTHER IN THE GULF OF MEXICO TO THE
WEST OF THE SCNTRL FL PENINSULA. RECENT NWD TREND WITH ERN
PANHANDLE CONVECTION A RESULT OF MID-LVL CYCLONIC FLOW AROUND
SERN U.S. MID-UPPER LVL LOW AS ERN GULF ACTIVITY HAS BEGUN TO
TRANSLATE MORE SEWD WITH 30-35 KT WNWLY MID-LVL FLOW. EXPECT
SCATTERED CONVECTION TO INCREASE IN COVERAGE AMIDST MODERATELY
UNSTABLE AIRMASS / 1500 - 2500 J/KG OF MUCAPE / JUST AHEAD OF
WEAK VORTICITY AXIS IN THE VICINITY OF THE STATIONARY FRONTAL
BOUNDARY ACROSS SWRN GA/NRN FL.



FURTHER SOUTH...CONVECTIVE BAND IN WRN GULF OF MEXICO IS THE
PRIMARY FEATURE OF INTEREST WEST OF REGION OF SUBSIDENCE OVER
MUCH OF THE PENINSULA THRU MUCH OF THE MRNG. AS SUBSIDENT REGION
HAS MOVED ENEWD THE PAST FEW HOURS SOME SHALLOW CONVECTION HAS
INCREASED IN COVERAGE AS THE ONSHORE FLOW HAS STRENGTHENED.
ALTHOUGH SOME SMALL HAIL IS POSSIBLE WITH THIS ACTIVITY...BELIEVE
THE PRIMARY THREAT WILL BE MARGINALLY STRONG DAMAGING WINDS IF
LINE CAN HOLD TOGETHER IN THE ERN GULF. HOWEVER...EXPECTED
DIVERGENT LOW-LVL FLOW OVER MUCH OF THE FL PENINSULA INDICATES A
RATHER WEAK BOUNDARY LAYER CONVERGENCE REGIME. IN
ADDITION...RECENT LIGHTNING / TRACKING TRENDS POINT TOWARDS THE
IMPULSE TO TRANSLATE SSEWD TOWARDS EXTREME SWRN FL/THE KEYS
REGION AT AROUND 30 KTS.

..NADEN.. 03/17/2003

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

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

29998393 30328425 30588406 30568332 30278282 29178219
28488175 27868142 27208122 26088126 25968161 26548222
27678283 28228289 28678279 29208322 29658370

Mesoscale Discussions in Florida, 2003Every mesoscale discussion in 2003

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.