Severe Thunderstorm Warning 124, NWS Tallahassee, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
330 PM EDT SAT JUL 22 2000

HIGHLY AMPLIFIED FLOW FOR THIS TIME OF YEAR ACROSS NORTH AMERICA TO
CONTINUE THROUGH THE FORECAST PERIOD...AND SEVERAL SHORT WAVES WILL
ROUND THE TOP OF THE WESTERN U.S. RIDGE...THEN DROP SOUTHEASTWARD
INTO THE MEAN TROF OVER THE EAST...ONE APPROACHING SUNDAY AND
ANOTHER ON MONDAY. THE EFFECT WILL BE TO FURTHER AMPLIFY THE
TROF...AND PUSH A WEAK FRONTAL BOUNDARY...CURRENTLY NORTH OF OUR
FORECAST AREA...A BIT CLOSER TO US OVER THE NEXT SEVERAL DAYS.
QUESTION IS HOW MUCH CLOSER. GIVEN THAT THE MEAN TROF AXIS SHOULD
REMAIN MORE TO THE WEST...PREFER A SOLUTION THAT KEEPS BOUNDARY TO
THE WEST AND NORTH AND A SOLUTION SOMEWHERE BETWEEN THE ETA AND AVN
FITS MY PRECONCEIVED IDEA THE BEST. A POTENTIAL WILD CARD IS A
MID-UPPER LEVEL CIRCULATION SHOWN ON THE WATER VAPOR IMAGERY
DEVELOPING IN THE CENTRAL GULF...AND GIVEN THE DEPTH OF THE TROF
OVER THE EASTERN U.S. I LIKE THE MRF SOLUTION OF CLOSING OF AN UPPER
LEVEL LOW SOMEWHERE AT THE BOTTOM OF THE TROF BY THE MIDDLE OF NEXT
WEEK.  SEABREEZE REGIME SEEMS TO HAVE TRANSITIONED TO A TYPE 4 WHICH
ALSO IMPLIES HIGHER POPS FURTHER NORTH AWAY FROM THE COASTAL AREAS
THAN DID THE PREVIOUS TYPE 8 PATTERN.

ZONE FORECAST...LOW LEVEL CONVERGENCE OVER EXTREME SOUTHEAST PORTION
OF OUR FORECAST AREA AND INTO THE APALACHEE BAY IS ALREADY PRODUCING
THUNDERSTORM ACTIVITY THERE. HOWEVER...GIVEN THE COMBINATION OF ALL
OF THE ABOVE...AND HOPEFULLY NOT TOO MUCH WISHFUL THINKING...WILL GO
WITH HIGHER POPS AND LOWER MAX TEMPERATURES...THUS CLOSER TO
CLIMATOLOGY THROUGH THE FORECAST AND EXTENDED FORECAST PERIODS.

MARINE...WITH WEAT LOW PRESSURE PERSISTING OVER AND TO THE NORTH AND
WEAK HIGH PRESSURE TO THE SOUTH...WILL REMAIN IN A LIGHT TO MODERATE
WEST TO SOUTHWEST FLOW.  THE MAIN THREAT WILL BE HIGHER WINDS AND
SEAS NEAR THE THUNDERSTORMS.

FIRE WEATHER...RELATIVELY HIGH HUMIDITIES AND MORE CLOUDS AND
SHOWERS SHOULD PRECLUDE HAVING TO HIGHLIGHT ANY MAJOR PROBLEM AREAS
THROUGH THE FORECAST PERIOD.

OUTLOOK...PERSISTENT STRONG TROF FORECAST FOR GULF OF ALASKA SHOULD
HELP MAINTAIN CURRENT MEAN RIDGE POSITION OR PERHAPS EVEN A LITTLE
FURTHER WEST...AND AN UNUSUALLY DEEP TROF OVER THE EAST...WITH AN
AXIS JUST TO THE WEST OF OUR FORECAST AREA. THUS I EXPECT THE TREND
TO MORE NORMAL TEMPERATURES AND HIGHER POPS TO PERSIST BEYOND THE
EXTENDED FORECAST PERIOD.

TLH 072 093 073 091 3535
PFN 075 090 074 089 1424
DHN 073 091 071 090 2324
ABY 072 093 072 089 2424
VLD 072 093 072 090 2535

.TLH...
AL...NONE.
GA...NONE.
FL...NONE.

PD