WPC Met Watch |
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Mesoscale Precipitation Discussion: #0035 (2017) |
(Issued at 1251 AM EST SUN JAN 22 2017
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MPD Selection |
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MESOSCALE PRECIPITATION DISCUSSION 0035
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1251 AM EST SUN JAN 22 2017
AREAS AFFECTED...SOUTHEAST AL...SOUTHERN GA...WESTERN FL PANHANDLE
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 220550Z - 221050Z
SUMMARY...BROAD LARGE SCALE ASCENT WITH EMBEDDED CONVECTIVE CELLS
MAY ALIGN FOR SHORT DURATIONS OF TRAINING PARTICULARLY OVER AREAS
OF SATURATED SOILS FROM YESTERDAY'S RAINFALL.
DISCUSSION...WV LOOP DENOTES STRONG IMPULSE WITH WARMING TEMPS
CROSSING S MS ATTM WITH A TRAILING SW-NE LOW TO MID-LEVEL SURGE
EXTENDING BACK ACROSS THE MOUTH OF THE MS RIVER. THIS
STRENGTHENING OF LOW LEVEL SWLY FLOW WILL STRENGTHEN LOW LEVEL JET
THAT IS ORIENTED NEARLY ORTHOGONAL TO THE WARM FRONT CROSSING SW
AL BEFORE IT FLATTENS E-W ALONG THE FL/GA LINE. AS SUCH CONTINUED
UPSTREAM DEVELOPMENT WITHIN THE WARM SECTOR WILL CROSS THE WARM
FRONT ISENTROPICALLY SUPPORTING FURTHER ELEVATED CONVECTION ACROSS
SE AL INTO SW GA FURTHER COMPOUNDING ONGOING FLOODING CONDITIONS
THERE. NEARER THE CENTER OF THE WAVE INCREASING CONVECTION IN
BROADER DIFFLUENT FLOW ACROSS SOUTH CENTRAL AL IS GENERATING
EXPANDING BROAD SHIELD OF PRECIPITATION WITH EMBEDDED CONVECTIVE
ELEMENTS...THIS AREA CONTINUES TO COOL IN IR AS IT LIFTS
NORTHEAST. IN DOING SO...THE INCREASINGLY EFFICIENT RAINFALL AREA
WILL CROSS AREAS OF EAST CENTRAL AL INTO W CENTRAL GA WHERE FFG
VALUES HAVE BEEN LESSENED FROM MGM TO FFC ALONG I-85 AS WELL AS
EAST TOWARD LFS WHERE 2-3" FELL LAST NIGHT. AS THE CELLS LIFT
NORTHEAST INTO MORE STABLE AIR IN CENTRAL GA...CONVECTION SHOULD
WANE AND REDUCE IN RAINFALL RATES AND TOTALS. HOWEVER...EXTENDED
MPD AREA OF CONCERN TO ENCOMPASS THE ATLANTA METRO ON THE LOWER
POSSIBILITY THAT THE FORCING NEAR THE APEX OF THE SHORTWAVE MAY
CROSS THE VICINITY WITH MODERATE RATES IN AN URBAN SETTING POSING
SOME FLOODING CONCERNS.
ACROSS S GA...SOME EMBEDDED ELEVATED SUPERCELLS CONTINUE TO TRACK
EAST NORTH OF THE E-W FRONTAL ZONE WITH SLIGHTLY SLOWER EASTWARD
PROGRESS AND LOCALIZED INCREASED FLOW...UPDRAFTS CONTINUE TO BE
QUITE EFFICIENT RAINFALL PRODUCERS WITH EOX RADAR SUGGESTING
1.5-2"/HR RATES WITH LIMITED HAIL CONTAMINATION BASED ON HCA. MID
TO UPPER LEVEL STEERING FLOW IS A BIT MORE WESTERLY ALLOWING FOR
ADDITIONAL TRAINING OF UPDRAFT CORES POSING CONTINUED FLASH
FLOODING THREAT. THIS IS FURTHER COMPOUNDED GIVEN THE BROAD
ISENTROPIC ASCENT ACROSS THE BOUNDARY TO ACTIVATE CONVECTION
UPSTREAM OF THESE CELLS TO PROLONG TRAINING SETUP INTO SE GA
GALLINA
ATTN...WFO...BMX...FFC...JAX...MOB...TAE...
ATTN...RFC...SERFC...
LAT...LON 33868445 33118366 32288411 32038243 31138176
31138295 31148438 30968470 30798514 30658588
30718680 31258706 31798776 32118744 32878625
Last Updated: 1251 AM EST SUN JAN 22 2017
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