265 FXUS61 KCAR 160811 AFDCAR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 411 AM EDT MON JUL 16 2012 .SYNOPSIS... A WEAK COLD FRONT AND TROUGH OF LOW PRESSURE WILL CROSS THE AREA TODAY. A STRONGER COLD FRONT WILL APPROACH ON TUESDAY AND CROSS THE AREA TUESDAY NIGHT. CANADIAN HIGH PRESSURE WITH MUCH COOLER AND DRIER AIR WILL RETURN FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... SHOWERS ACROSS THE FA ERLY THIS AM CONT TO MOVE EWRD W/ COVERAGE DECREASING DURING THE PAST FEW HRS. WITH THIS DECREASE IN COVERAGE...LGTNG ACTIVITY HAS DIMINISHED AS WELL... WILL LIKELY BE ABLE TO DROP THE CURRENT FFW FOR PORTIONS OF SW PISCATAQUIS CNTY SHORTLY BASED ON RECENT AND CURRENT TRENDS. OTHRWS...WEAK SFC COLD FRONT AND TROF OF LOW PRES WILL CONT TO SLOWLY CROSS THE AREA TDY. ONLY MODEST CAPES OF 500-1000 J/KG AND WEAK SHEAR SUGGESTS ANY CONVECTION TDY SHOULD BE MOSTLY GARDEN VARIETY IN NATURE W/ SPC SHOWING OUR AREA IN JUST A GENERAL OUTLOOK W/ THE STRONGER CONVECTION LIKELY LATER TUE (SEE SHORT TERM SECTION BLO). BY TNGT...THESE FEATURES HAVE MOVD E AND SE OF THE AREA W/ A VRY WEAK RIDGE OF HIGH PRES EXPECTED TO BUILD BRIEFLY OVR THE REGION. EXPECT A RATHER MUGGY NIGHT W/ PTCHY FOG ACROSS THE AREA AND BEST CHC POPS SE DURING THE EVE HRS AS THE WEAK SFC COLD FRONT EXITS THIS AREA. NXT SYSTEM ALREADY COMING INTO THE PICTURE BY ERLY TUE W/ CHC POPS FAR NWRN AREAS BY 12Z. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... THE COLD FRONT FROM MONDAY WILL STALL NEAR THE COAST AND WILL LIFT BACK NORTHWARD TUESDAY. THIS WILL PRODUCE SOME STABLE CLOUD LAYERS AND SHOWERS IN NORTHERN ZONES THAT WILL LIMIT HEATING IN THE MORNING AND EARLY AFTERNOON. HOWEVER...AS LOW PRESSURE MOVES ALONG THE WARM FRONT FROM QUEBEC TOWARDS NORTHERN MAINE...EXPECT SOME SUNNY BREAKS DURING THE AFTERNOON. THIS WILL DESTABILIZE THE ATMOSPHERE. WITH THIS DESTABILIZATION...NUMEROUS INGREDIENTS WILL BE IN PLACE FOR SEVERE WEATHER TUESDAY AFTERNOON AND EVENING. BOTH 0 TO 1 KM AND 0 TO 6 KM SHEAR VALUES ARE EXPECTED TO REACH VALUES ASSOCIATED WITH SEVERE STORMS. AN UPPER LEVEL JET MOVING OVER NORTHERN MAINE DURING THE AFTERNOON IS EXPECTED TO BRING DIVERGENCE ALOFT. OTHER INGREDIENTS SUCH AS AN H850 LLJ...STEEP LAPSE RATE PROFILES...USUALLY HIGH HELICITY...AN 850 THERMAL RIDGE...DEW POINTS IN THE UPPER 60S...AND FORCING PROVIDED BY A VERY STRONG COLD FRONT ALL COMBINE TO PRODUCE A POTENTIALLY EVENTFUL LATE AFTERNOON AND EVENING. SUPERCELLS WILL BE POSSIBLE IF SUFFICIENT HEATING DOES OCCUR IN THE AFTERNOON AHEAD OF THE FRONT. INCLUDED GUSTY WINDS WORDING IN FORECAST FOR NOW. THE POTENTIAL FOR HAIL LOOKS BETTER FURTHER WEST OF THE FORECAST AREA...BUT ENHANCED WORDING FOR HAIL WILL HAVE TO BE CONSIDERED FOR THE NEXT FORECAST UPDATE. THIS VERY STRONG FRONT WILL MOVE ACROSS THE FORECAST AREA TUESDAY NIGHT INTO EARLY WEDNESDAY WITH THUNDERSTORMS ENDING WELL INTO THE NIGHT. THE FRONT AND ASSOCIATED CLOUD COVER IS EXPECTED TO HAVE MOVED OFF THE COAST BY MIDDAY WEDNESDAY AND WILL FINALLY BREAK THE WARM SPELL AS HIGHS FOR THE REMAINDER OF THE WEEK WILL DROP TO THE 70S WITH LOW HUMIDITY. THERE ARE TWO CONCERNS FOR WEDNESDAY. FIRST...WINDS WILL GUST UP TO 25 MPH IN THE NORTHWEST WINDS BEHIND THE FRONT. SECOND...THE FRONT MAY STALL NEAR THE COAST AND KEEP CLOUDS AND EVEN SOME RAIN ALONG THE COAST WEDNESDAY INTO WEDNESDAY EVENING. WITH REGARD TO THIS SECOND CONCERN...HAVE GONE WITH THE MORE OPTIMISTIC SCENARIO OF THE CLOUDS PUSHING OFFSHORE...BUT THERE IS STILL UNCERTAINTY ON HOW FAST THE FRONT WILL CLEAR THE COAST. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... DRY...PLEASANT TEMPERATURES...LOW HUMIDITY AND GENERALLY UNEVENTFUL. A FEW LIGHT RAINSHOWERS AND CLOUDY SKIES ARE POSSIBLE TOWARDS THE CROWN OF MAINE LATER THURSDAY INTO FRIDAY...BUT WILL NOT INTRODUCE POPS AT THIS TIME. WARMER AIR RETURNS FOR THE WEEKEND WITH HIGHS RETURNING TOWARDS 80F IN THE CWA IN A SOUTHWEST SURFACE FLOW. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... NEAR TERM: IFR CONDS ONLY AT KBHB ATTM W/ IFR CONDS PSBL AT KBGR NXT FEW HRS INTO THE ERLY AM. OTHRWS...ALL REMAINING SITES VFR ATTM W/ MVFR IN PTCHY FOG/MIST/SHOWERS PSBL THRU THE ERLY AM HRS. MAINLY VFR AT ALL THE TAF SITES TODAY INTO TNGT OUTSIDE OF ANY SHOWERS THO KBHB SHOULD BE SLOW TO IMPROVE W/ IFR EXPECTED TO RETURN BY LATE AFTN/ERLY EVE. PTCHY FOG AND PSBL MVFR AGAIN PSBL AT THE REMAINING TAF SITES LATER TNGT INTO ERLY TUE AM. SHORT TERM: LLWS AND SEVERE AFTERNOON AND EVENING THUNDERSTORMS ARE CONCERNS FOR TUESDAY. IFR CONDITIONS ARE POSSIBLE TUESDAY NIGHT BEFORE A STRONG COLD FRONT BRINGS VFR FOR THE REMAINDER OF THE PERIOD. && .MARINE... NEAR TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA LEVELS THROUGH TONIGHT. HUMID AIR OVER THE WATERS WILL LIKELY RESULT IN AREAS OF FOG THROUGH TONIGHT AS WELL. SHORT TERM: SCA FOR HAZARDOUS SEAS POSSIBLE TUESDAY NIGHT INTO WEDNESDAY ALONG WITH SOME WIND GUSTS REACHING 20 KTS. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...KHW SHORT TERM...MCW LONG TERM...MCW AVIATION...KHW MARINE...KHW/MCW