Area Forecast Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KPBZ 202329
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
729 PM EDT MON OCT 20 2014

.SYNOPSIS...
RAINY AND COOL THROUGH MID-WEEK WHEN UPPER LOW PRESSURE SYSTEM
SHIFTS EASTWARD. WARMER AND DRIER WEATHER IS EXPECTED TOWARDS THE
END OF THE WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
EARLY EVENING UPDATE TO ADD CAT POPS FARTHER SOUTH TONIGHT BASED
ON RADAR TRENDS SHOWING BANDS OF SHOWERS DEVELOPING WELL INTO SOUTHERN
OHIO. ALSO SPEED UP TIMING FOR SHOWERS INTO RIDGES EARLY TONIGHT.
MODEST QPF ADDED. NO CHANGES TO TEMPERATURES OR WINDS. PREVIOUS
DISCO BELOW.


SW TROF AND ATTENDANT VORT MAX EVIDENT ON WV IMAGERY CURRENTLY
SWINGING THROUGH ERN INDIANA SOUTH OF THE SFC NEARING LAKE HURON.
MID-LEVEL DEFORMATION PRODUCING HIGH CLOUDS AHEAD OF TROF AXIS
OVER WV AND SW PA WILL PUSH EAST TONIGHT. THOSE CLOUDS WILL BE
REPLACED BY LOWER CLOUDS THIS EVENING KEEPING TEMPS MODERATED.

RADAR RETURNS HAVE BEEN QUITE NUMEROUS TODAY...BUT LITTLE MORE
THAN VIRGA HAS BEEN REPORTED UP TO THIS POINT AS DRY AIR FROM THE
MID LEVELS DOWN ARE KEEPING ANY RAIN SHOWERS FROM REACHING THE
GROUND. RAIN SHOWERS ASSOCIATED WITH THE SW TROF ARE SHOWING UP
OVER WRN OHIO AND ARE TIMED TO REACH OUR WRN PERIPHERY BY ABOUT
21Z. BY 00Z ALL OF THE NEAR TERM MODELS HAVE THE SW TROF AXIS
THROUGH ERN OH WITH RAIN SHOWERS OVERSPREADING THE AREA FROM THE
WNW. DEEPER MOISTURE AVAILABILITY AND BETTER FORCING WILL REMAIN
CLOSER TO THE LOW NEAR LAKE ERIE...THUS WILL CONTINUE THE
CATEGORICAL POPS THERE. ALTHOUGH THE MID TO UPPER LEVEL MOISTURE
BEGINS TO OUTRUN THE TROF AXIS ACROSS OUR SOUTH...ENOUGH MOISTURE
IS AVAILABLE TO PRODUCE SHOWERS ACROSS NRN WV. WILL NOT DEVIATE
FROM THE LIKELY POPS.

TONIGHT THE SFC LOW IS PULLED SOUTH AWAY FROM THE GREAT LAKES AS
THE UPPER LOW BEGINS TO CUT-OFF. AS THIS HAPPENS...ABUNDANT LLVL
MOISTURE WILL SHIFT OVER THE AREA KEEPING CLOUDS AND RAIN IN THE
FORECAST. AS THE UPPER LOW SLOWLY PASSES TUES...THE SFC-H8 LOW CORE
SHIFTS EAST BRINGING AN UPSLOPE COMPONENT TO THE LLVL WIND FIELD.
WILL KEEP CATEGORICAL POPS IN FOR THE SE RIDGES AS A RESULT. DRIEST
LOCATION IN THE CWA TUES LOOKS TO BE OVER ERN OHIO WHERE DRIER AIR
ALOFT BEGINS FEEDING INTO THE UPPER LOW WHICH MAY WORK TO SUPPRESS
ADDITIONAL SHOWERS.
TAX

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
COLD AND RELATIVELY UNSTABLE NORTHWEST TO NORTHERLY FLOW CONTINUES
OVER THE AREA FROM TUESDAY NIGHT INTO WEDNESDAY NIGHT. WHILE THE
MID-LEVEL COLD POOL BEGINS TO DEPART TO THE EAST BY WEDNESDAY AND
WEDNESDAY NIGHT...AMPLY BOUNDARY LAYER MOISTURE...LOW LEVEL
INSTABILITY...AND UPSLOPE FLOW SHOULD MAINTAIN LOW END CHANCES OF
SHOWERS IN THE LOWER ELEVATIONS AND FAIRLY GOOD CHANCES OF SHOWERS
IN THE RIDGES. AS SHEAR INCREASES AFTER THIS TIME...MID-LEVEL
RIDGING STARTS TO IMPINGE...AND DRIER BOUNDARY LAYER AIR FINALLY
STARTS TO WORK INTO THE REGION...SHOWER CHANCES DWINDLE TO LESS
THAN MENTIONABLE BEYOND WEDNESDAY NIGHT.

THE LATTER HALF OF THE WEEK NOW LOOKS RATHER DRY...WITH
TEMPERATURES MODERATING TOWARD NORMAL AS SUNSHINE SHOULD FINALLY
MAKE A RETURN TO THE UPPER OHIO VALLEY. FRIES

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
EWD PROGRESS OF THE MID-WEEK UPR LOW WITH EXPANDING RIDGE OVR THE
CNTRL CONUS SHOULD ENSURE A GENLY DRY AND SEASONABLY COOL CLOSE TO
THE WEEK. TWEAKED WPC NMBRS WERE USED TO REPRESENT THE LONG TERM
PD.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
VFR AT THE START...BUT FLIGHT CONDITIONS ARE EXPECTED TO
DETERIORATE THIS EVENING AS A SHORTWAVE WITH ASSOCIATED SHOWERS
PASSES THROUGH. HAVE ALL SITES DROPPING TO MVFR...AND SEVERAL
SHOULD REACH IFR ON EITHER A PREVAILING OR TEMPORARY BASIS AFTER
06Z OR SO. THE ARRIVAL OF AN UPPER LOW ON TUESDAY WILL MAINTAIN
MVFR CIGS INTO AT LEAST EARLY AFTERNOON. HAVE IMPROVMENT TO VFR
LATE IN THE TAFS BUT COULD EASILY SEE MVFR LINGER. LIGHT S/SW
WINDS WILL SHIFT AROUND TO W BY 12Z AND EVEN TURN WNW BY AFTERNOON.

.AVIATION /TUESDAY THROUGH FRIDAY/...
PERIODIC RESTRICTIONS ARE POSSIBLE THROUGH MID WEEK AS AN UPPER LOW
DRIFTS ACROSS THE REGION.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.