Area Forecast Discussion
Issued by NWS

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000
FXUS61 KPBZ 291029
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
629 AM EDT TUE JUL 29 2014

.SYNOPSIS...
A SERIES OF DISTURBANCES IN COOL NORTHWEST FLOW WILL BRING SHOWER
CHANCES THROUGH THE MIDDLE OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
WITH HIGH PRESSURE STILL WELL OFF TO THE WEST THIS MORNING...SFC
FLOW NEVER FULLY CALMED THUS INHIBITING FULL RADIATIONAL COOLING
POTENTIAL. REGARDLESS...THE AREA WILL BE STARTING THE DAY WITH TEMPERATURES
NEARLY 10 DEGREES BELOW THE AVERAGE LOWS.

A MOSTLY DRY FORECAST TODAY...ALTHOUGH A WEAK MID-LEVEL WAVE WILL
DROP OUT OF THE NORTH REACHING OUR NWRN PERIPHERY BY EARLY
AFTERNOON. DEEPER MOISTURE IS RELATIVELY SPARSE AND LAGS BEHIND...BUT
ENOUGH LLVL MOISTURE AND STEEP LLVL LAPSE RATES SHOULD GENERATE
DIURNAL CU ALONG WITH SOME ISOLATED SHOWERS PRIMARILY NORTH OF I80.
H85 TEMPS PROGGED BY THE NEAR TERM MODELS TO BE IN THE 5-7C RANGE OR
ABOUT 2SD BELOW THE MEAN. THIS UNUSUALLY COLD AIR UNDER A NORTHWEST
FLOW REGIME WILL KEEP DAYTIME HIGHS IN CHECK DESPITE THE MOSTLY
SUNNY CONDITIONS. ONCE AGAIN WE WILL BE LOOKING AT DAYTIME HIGHS
ABOUT 10 DEGREES BELOW AVERAGE.
TAX

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
MEAN EASTERN U.S. TROUGH IS MAINTAINED THROUGH THIS
PERIOD...ALTHOUGH THE H500 AXIS RELOADS TO THE WEST BY FRIDAY.
POPS WILL TAKE ON A HIGHLY DIURNAL CHARACTER IN THIS PATTERN. WHILE
THIS IS HAPPENING...HEIGHTS RISE WITH TIME. THIS WILL ALLOW
TEMPERATURES TO MODERATE BACK TOWARDS SEASONABLE LEVELS BY FRIDAY.
DECENT SPOKE OF ENERGY ROTATES THROUGH THE TROUGH AND ACROSS THE
CWA WEDNESDAY AFTERNOON...WITH SCATTERED SHOWERS EXPECTED CWA-
WIDE. UPPED POPS TO HIGH CHANCE IN THE NORTH...WHERE LIKELY POPS
MAY BECOME APPROPRIATE IN FUTURE FORECASTS. LOW LEVEL LAPSE RATES
ARE NOT AS ROBUST AS TUESDAY...BUT THERE SHOULD BE ENOUGH
INSTABILITY FOR ISOLATED STORMS WHICH COULD EVEN CONTAIN SMALL
HAIL. AFTER WAVE DEPARTS...THURSDAY SHOULD BE LESS ACTIVE WITH
PRECIP NORTH OF I-70 FOR THE MOST PART. KEPT ISOLATED THUNDER
AGAIN...WITH BETTER LOW LEVEL LAPSE RATES. ON FRIDAY...A WAVE
TRIES TO ROTATE ACROSS THE SOUTHEAST U.S. AT THE BASE OF THE
TROUGH AND THEN RIDE UP THE APPALACHIANS. THIS MAY ALLOW FOR
SLIGHTLY BETTER SHRA COVERAGE ALONG THE SOUTHEAST RIDGES DURING
THE AFTERNOON...OTHERWISE THE NORTHERN COUNTIES WILL ONCE AGAIN BE
FAVORED.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
ALTHOUGH THE MEAN TROUGH MAINTAINS THROUGH THE WEEKEND...H500
HEIGHTS WILL HAVE RECOVERED TO THE POINT THAT ALLOWS SEASONABLE
TEMPERATURES. DEWPOINT WILL REMAIN COMFORTABLE WITHOUT ANY
SIGNIFICANT MOISTURE INFLUX FROM THE SOUTH. A SHORTWAVE MAY PROVIDE
DECENT SHRA/TSRA COVERAGE SATURDAY AFTERNOON/EVENING...WHILE
SUNDAY WILL SEE A RETURN OF MORE SPARSE PRECIPITATION BEHIND THIS
DISTURBANCE. THERE ARE HINTS THAT THE TROUGH MAY TRY TO LIFT OUT
EARLY NEXT WEEK...AT LEAST TEMPORARILY. THIS MAY LEAD TO LITTLE OR
NO AFTERNOON PRECIP BY TUESDAY...AS WELL AS CONTINUED SEASONABLE
WARMTH.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
PRIMARILY VFR CONDITIONS THIS MORNING AS CIGS GENERALLY STAYING
4KFT AND HIGHER. A COUPLE OF THE MORE SHELTERED
TERMINALS SUCH AS DUJ AND LBE COULD SEE A DIP IN CIGS AS SHALLOW
STRATUS FORMS CLOSER TO THE HIGH TERRAIN. PREVAILING VFR EXPECTED
MID-MORNING ON AS NORTHWEST FLOW AND COOLER AIR ALOFT WILL ALLOW
FOR THE DEVELOPMENT OF MID-LEVEL CU.

OUTLOOK.../TUESDAY NIGHT THROUGH SATURDAY/...
NO WDSPRD RSTRNS EXPD.

&&

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

&&

$$





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