Area Forecast Discussion
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000 FXUS61 KPBZ 131456 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 1056 AM EDT SUN APR 13 2014 .SYNOPSIS... HIGH PRESSURE WILL PROVIDE WARM AND DRY CONDITIONS THROUGH EARLY MONDAY UNTIL A COLD FRONT BRINGS SHOWERS AND MUCH COLDER AIR ON TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE VAST MAJORITY OF SHOWER ACTIVITY HAS PUSHED EAST OF THE AREA OVER THE PAST HALF OF AN HOUR WITH NO ADDITIONAL UPSTREAM ACTIVITY PARTICULARLY EVIDENT ON THE REGIONAL RADAR MOSAICS. AS THIS OCCURS AND THE CAP PERPETUATES INTO THE AFTERNOON IN THE 6-8 KFT RANGE...AND MIXING INCREASES BELOW 850 MB...WE SHOULD EASILY MIX OUT THE ROUGHLY +14C AT 850 MB. THIS MEANS A FAIRLY WARM...ALBEIT NOT PARTICULARLY SUNNY...AFTERNOON LOOKS TO BE IN STORE FOR THE CWA. WINDS WILL CONTINUE TO BECOME INCREASINGLY GUSTY DUE TO UNSTABLE LOW LEVELS...HOWEVER WITH DEWPOINTS NOW PUSHING 50F ACROSS THE AREA...WIND/RH CONCERNS FOR FIRE WEATHER WILL BE MINIMIZED. FRIES && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... STILL HAVE TO DEAL WITH TIMING ISSUES CONCERNING THE ONSET OF SHOWERS ON MONDAY. ATMOSPHERE AHEAD OF FRONT IS RATHER DRY AND WILL TAKE SOME TIME TO SATURATE. THIS COULD PRODUCE A SITUATION WHERE SHOWERS THAT DEVELOP MONDAY MORNING WILL DISSIPATE/EVAPORATE AS THEY MOVE EASTWARD. IT IS BEGINNING TO LOOK MORE AND MORE LIKE MOST OF THE SHOWER/THUNDERSTORM ACTIVITY WILL HOLD OFF UNTIL MONDAY AFTERNOON. AGAIN...THERE WILL BE AN INCREASED RISK FOR STRONG WIND GUSTS MONDAY AS MIXING HEIGHTS RISE ABOVE 4000FT WHICH WILL EASILY TAP INTO THE STRONG WINDS ASSOCIATED WITH A LOW-LEVEL JET ON THE EASTERN SIDE OF COLD FRONT. WINDS GUSTS TO 40 MPH ARE NOT OUT OF THE QUESTION MONDAY AFTERNOON. ATMOSPHERE IS NOT PARTICULARLY UNSTABLE ON MONDAY WITH LI`S AROUND -1 TO -2 AND CAPES OF 200 TO 300 J/KG. THE K INDEX DOES RISE INTO THE 30S LATER MONDAY AFTERNOON...WITH THE MU-CAPE RISING ABOVE 500 J/KG AND THE BULK SHEAR AT AROUND 40KTS. PRE-FRONTAL CLOUDS WILL GREATLY LIMIT THE AMOUNT OF SUNSHINE MONDAY AND LIKELY HAMPER OUR ABILITY TO REACH CONVECTIVE TEMPS. HOWEVER...WITH A SOMEWHAT DESTABILIZED ATMOSPHERE AND PLENTY OF SHEAR STILL THINK THAT THUNDERSTORMS ARE POSSIBLE. ANY BREAKS IN THE CLOUD COVER... ALLOWING FOR A RISE IN SURFACE TEMPS...COULD AID IN PRODUCING SOME ISO STRONG STORMS. WIDE SPREAD RAIN SHOWERS WILL MOVE THROUGH MONDAY NIGHT. THUNDERSTORM THREAT WILL DIMINISH AS ATMOSPHERE STABILIZES AND SHEAR VALUES DECREASE. MUCH COLDER AIR WILL MOVE IN BEHIND THE FRONT ON TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A WARMING TREND BEGINS ON WEDNESDAY WITH DRY CONDITIONS EXPECTED THROUGH FRIDAY. MODEL DIFFERENCES ARE PROVIDING A LOW CONFIDENCE FORECAST FORECAST FOR SATURDAY. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... VFR CONDITIONS ALONG WITH SOUTH TO SOUTHWEST WINDS CAN BE EXPECTED TODAY...WITH GUSTS TO BETWEEN 20 AND 30KTS DURING THE AFTERNOON. .OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... RSTRNS ARE EXPD WITH A CROSSING CDFNT MON AND TUE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$

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