550 FXUS62 KRAH 072002 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 302 PM EST THU FEB 7 2013 .SYNOPSIS... AN AREA OF LOW PRESSURE OVER THE NORTHERN GULF OF MEXICO WILL MOVE NORTHEASTWARD ACROSS THE SOUTHEAST U.S. TODAY...ALONG THE NORTH CAROLINA COAST TONIGHT. THE LOW WILL INTENSIFY ON FRIDAY AS IT TRACKS OFF THE MID-ATLANTIC COAST. HIGH PRESSURE WILL SETTLE OVER THE AREA THROUGH THE WEEKEND. && .NEAR TERM /THROUGH FRIDAY NIGHT/... AS OF 301 PM THURSDAY... TEMPERATURES HAVE STRUGGLED TO GET OUT OF THE 40S OVER MUCH OF THE AREA... AS THE COLD AIR DAMMING WEDGE REMAINS IN PLACE. CLOUDS REMAIN ACROSS MUCH OF THE AREA... AND WILL CONTINUE TO THICKEN AND LOWER AS A NORTHERN GULF OF MEXICO LOW PRESSURE SYSTEM APPROACHES THE AREA ALONG THE SOUTHEAST COAST OVERNIGHT... AND WILL BE IN THE VICINITY OF THE OUTER BANKS AT 12Z FRIDAY. HEAVIEST RAINS STILL LOOK TO BE BETWEEN 00Z AND 06Z OVER THE AREA... IN ASSOCIATION WITH GOOD ISENTROPIC LIFT. WINDS WILL GUST AROUND 20 KTS ACROSS THE COASTAL PLAIN WITH PROXIMITY TO THE TIGHT GRADIENT SURROUNDING THE APPROACHING LOW PRESSURE SYSTEM. LOWS MID 30S TO LOWER 40S. CLOUDS WILL LINGER THROUGH THE MORNING AND AFTERNOON HOURS FRIDAY... AND THICKNESSES INDICATE HIGHS A FEW DEGREES WARMER THAN TODAY...YIELDING MID 50S. A COLD FRONT ASSOCIATED WITH A TRAILING NORTHERN STREAM WAVE CROSSES THE AREA FRIDAY EVENING... AS THE TWO STORMS PHASE OFF THE MIDATLANTIC COAST. LACK OF DEEP MOISTURE WILL LIKELY PRECLUDE SHOWERS IN ASSOCIATION WITH THE FRONTAL PASSAGE. SUBSIDENCE AND DRYING IN THE WAKE OF THE FRONTAL PASSAGE WILL BEGIN TO SCOUR REMAINING CLOUDS OUT OF THE AREA AFTER 00Z SATURDAY... PROVIDING GOOD COOLING CONDITIONS OVERNIGHT... IN ADDITION TO COLD ADVECTION. LOWS UPPER 20S TO LOW 30S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... AS OF 155 PM THURSDAY... RIDGING ALOFT...AND UNDERLYING CONTINENTAL POLAR SURFACE HIGH PRESSURE...WILL EXPAND FROM THE MS VALLEY EASTWARD TO THE EAST COAST THROUGH THE WEEKEND. DEEP DRYNESS AND CLEAR SKIES SAT WILL YIELD TO INCREASING CIRRUS IN ADVANCE OF A SHEAR VORTICITY-INDUCED SOUTHERN STREAM WAVE BY LATE SAT NIGHT-SUN. THE FRESH CP HIGH WILL YIELD BELOW AVERAGE TEMPERATURES SAT AND SAT NIGHT...INCLUDING WIDESPREAD 20S SUN MORNING IN NEAR OPTIMAL RADIATIONAL COOLING CONDITIONS THAT WILL BE HINDERED ONLY BY THE AFOREMENTIONED INCREASING CIRRUS LATE. CONTINUED DRY WITH PERIODS OF CIRRUS ON SUN...WITH AIR MASS MODIFICATION TO AOA AVERAGE LEVELS FOR HIGH TEMPERATURES. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... AS OF 250 AM THURSDAY... A LONGWAVE TROUGH OVER THE WESTERN CONUS WILL GRADUALLY ADVANCE EASTWARD THROUGH THE MIDDLE OF NEXT WEEK. A LEAD SHORTWAVE WILL EJECT INTO THE CENTRAL PLAINS LATE SUNDAY INTO MONDAY...WITH THE ASSOCIATED SURFACE LOW TRACKING NORTHEASTWARD THROUGH THE GREAT LAKES AND INTO THE NORTHEAST US BY TUESDAY. THIS WILL PROPEL A SURFACE FRONT INTO CENTRAL NC MONDAY AND TUESDAY. INCREASING ISENTROPIC LIFT OVER THE RESIDUAL SURFACE RIDGE WILL RESULT IN PRECIP CHANCES INCREASING SUNDAY NIGHT AND THEN PERSISTING THROUGH MONDAY AS THE FRONT CROSSES THE AREA. ALTHOUGH THERE ARE SOME MODEL DIFFERENCES...IT APPEARS THE FRONT WILL THEN SETTLE SOMEWHERE ALONG OR JUST SOUTHEAST OF THE FORECAST AREA THROUGH WEDNESDAY. AS THE MID LEVEL TROUGH SLOWLY MOVES EASTWARD...MULTIPLE WAVES OF LOW PRESSURE/DISTURBANCES WILL MOVE ALONG THE BOUNDARY WITHIN THE DEEP SOUTHWESTERLY FLOW. AS STATED ABOVE...THERE ARE MODEL DIFFERENCES...BUT NEVERTHELESS...IT APPEARS THE REGION WILL SEE AN EXTENDED PERIOD OF UNSETTLED WEATHER NEXT WEEK...EVEN THOUGH EXACT DETAILS WILL STILL HAVE TO BE IRONED OUT OVER THE NEXT SEVERAL DAYS. TEMPS WILL ULTIMATELY DEPEND ON THE AMOUNT OF PRECIP AND CLOUD COVER...BUT GIVEN THE DEEP SOUTHERLY TRANSPORT IN ADVANCE OF THE MID LEVEL TROUGH...TEMPS SHOULD BE ABOVE NORMAL FOR MUCH OF THE PERIOD. && .AVIATION /18Z THURSDAY THROUGH MONDAY/... AS OF 1255 PM THURSDAY... LOW PRESSURE OVER THE NORTHERN GULF OF MEXICO WILL MOVE ALONG THE SOUTHEAST COAST OVERNIGHT... REACHING THE OUTER BANKS AT 12Z. CLOUDS WILL CONTINUE TO THICKEN AND LOWER THIS AFTERNOON... DROPPING CIGS TO IFR AROUND 00Z FRIDAY... WITH RAIN MOVING IN FROM SOUTHWEST TO NORTHEAST. WINDS WILL GUST TO 15 TO 20 KTS OVERNIGHT AT KFAY... KRWI... AND LIKELY KRDU AS WELL. RAIN WILL EXIT THE REGION TOMORROW MORNING... WITH CIGS LIFTING TO MVFR AROUND 18Z. CONDITIONS WILL IMPROVE TO VFR FRIDAY NIGHT AS HIGH PRESSURE BUILDS IN TO THE AREA FOR THE WEEKEND. THE NEXT CHANCE FOR ADVERSE CONDITIONS WILL BE SUNDAY NIGHT INTO MONDAY AS A FRONTAL SYSTEM ENTERS THE REGION. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE && $$ SYNOPSIS...BLS NEAR TERM...SEC SHORT TERM...MWS LONG TERM...KRR AVIATION...SEC