000 FXUS63 KGRR 081640 AFDGRR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1140 AM EST SUN NOV 8 2009 LATEST UPDATE...AVIATION... .SYNOPSIS...(359 AM EST SUN NOV 8 2009) AFTER SOME EARLY MORNING FOG...TODAY WILL BE ANOTHER PLEASANT FALL DAY WITH SUNSHINE AND TEMPERATURES WELL INTO THE 60S OR APPROACHING 70. A COLD FRONT WILL DROP ACROSS THE REGION ON MONDAY BRINGING SLIGHTLY COOLER TEMPERATURES AND A CHANCE FOR A BRIEF SHOWER. AS THE FRONT SLIPS INTO SOUTHERN LOWER MICHIGAN AND WAVE OF LOW PRESSURE WILL APPROACH ALONG IT. DUE TO THIS LOW AREAS ALONG I-94 WILL GET A BETTER CHANCE OF A SOAKING RAIN LATE MONDAY NIGHT INTO EARLY TUESDAY. && .SHORT TERM...(655 AM EST SUN NOV 8 2009) (TODAY THROUGH TUESDAY) MAIN CONCERNS WERE THE DENSE FOG EARLY THIS MORNING...FOLLOWED BY THE AFFECTS OF A COLD FRONT THAT CROSSES THE REGION MONDAY AND MONDAY NIGHT. THE MODELS SWING A SHORT WAVE ALONG THE FRONT AS IT IS EXITING THE CWA...WHICH COULD LEAD TO A MORE MODERATE RAIN IN THE SOUTHERN CWA. THIS MORNINGS DENSE FOG HAS EXPANDED TO THE ENTIRE REGION. WILL UPDATE THE FORECAST AND INCLUDE ALL ZONES IN THE DENSE FOG ADVISORY. THE SATELLITE SHOWS VERY LITTLE CLOUD COVER ABOVE THE FOG...AND WITH INCREASING MIXING BY MID MORNING THE FOG SHOULD ERODE FAIRLY QUICKLY. MOST AREAS SHOULD BE AT OR ABOVE ONE MILE BY 9 AM...AT THE ADVISORY EXPIRATION TIME. BY 10 AM THE SUN SHOULD BE ABLE TO BREAK THROUGH AND REST OF THE DAY WILL BE VERY PLEASANT. A WARM FRONT WILL LIFT NORTH TOWARD I-96 BY THE END OF THE DAY. THE MODELS HAVE BACKED OFF ON THE AMOUNT OF LOW LEVEL CLOUDS EXPECTED WITH THIS FEATURE. SO WILL GO WITH A MOSTLY SUNNY FORECAST...WITH JUST SOME MID AND HI CLOUDS. TEMPS REACHED WELL INTO THE 60S ON SATURDAY AND I SEE NO REASON THAT WON/T HAPPEN AGAIN TODAY...AND IT SHOULD EVEN BE A COUPLE DEGREES WARMER TODAY. SEVERAL AREAS COULD APPROACH THE 70 DEGREE MARK. THE ATTENTION THEN TURNS TO THE MONDAY COLD FRONT. THIS SYSTEM IS BEGINNING TO LOOK EVEN WEAKER AS IT INITIALLY MOVES IN. THE MOISTURE DEPTH LOOKS TO BE THE MAJOR ISSUE AND THE AMOUNT OF RAIN ASSOCIATED WITH IT MAY BE LIMITED. HAVE BACKED OFF ON POPS FOR MONDAY TO ONLY SLIGHT CHANCE ACROSS THE NORTHERN HALF IN THE AFTERNOON. THE FRONT STALLS JUST TO OUR SOUTH MONDAY NIGHT AS A SHORT WAVE RIDES ALONG IT. THE GFS WAS DEEPER AND FASTER WITH THE WAVE...WHICH IS SOMEWHAT ODD. SO HAVE GONE MORE ALONG THE LINES OF THE NAM WITH THE TIMING OF THE WAVE. WITH THIS IN MIND HAVE BUMP POPS TO LIKELY FOR LATE MONDAY NIGHT INTO EARLY TUESDAY ACROSS THE SOUTHERN TWO ROWS OF COUNTIES. FURTHER NORTH...A LARGE AREA OF HIGH PRESSURE WILL BE MOVING IN BEHIND THE FRONT. WITH A DRY NORTHEAST FLOW DEVELOPING THE NORTHERN CWA WILL SEE CLEARING LATE MONDAY NIGHT. THIS HIGH EVENTUALLY MOVES OVERHEAD TUESDAY AFTERNOON AND PUSHES ANY RAIN OVER SOUTHERN LOWER OUT OF THE REGION. && .LONG TERM...(359 AM EST SUN NOV 8 2009) (TUESDAY NIGHT THROUGH SATURDAY) THE MAIN CHALLENGE IN THE LONG TERM DEALS WITH THE TEMPERATURES FOR THE END OF THE WEEK. RECENT TREND IN THE HIGH RES EURO SHOWS AN IMPRESSIVE SURGE OF WARM AIR LIFTING INTO LOWER MICHIGAN STARTING THURSDAY AND CONTINUING INTO FRIDAY. THE GFS HOWEVER FAVORS ONLY A MARGINAL WARMUP. THE 00Z FIM RUN DOES COME MORE IN LINE WITH THE HIGH RES EURO. AT THIS POINT I WILL RAISE TEMPERATURE SEVERAL DEGREES FOR THU...AND I BUMPED UP WINDS DUE TO THE ANTICIPATED STRONGER WARM AIR ADVECTION. IF THE HIGH RES EURO ENDS UP RIGHT FRI WILL BE AT LEAST AS WARM AS SATURDAY WAS THIS WEEKEND. WE DO NOT EDIT DAY 6 GRIDS ON THE MID SHIFT SO I LEFT THE TEMPERATURES ALONE FOR FRI. && .AVIATION...(1140 AM EST SUN NOV 8 2009) VFR CONDITIONS WILL CONTINUE AT ALL TAF SITES THIS AFTERNOON AND EVENING. SOME MVFR FOG IS EXPECTED OVERNIGHT WITH MOSTLY CLEAR SKIES. WIDESPREAD IFR OR LOWER CONDITIONS ARE NOT ANTICIPATED SINCE FLOW AND MIXING WILL BE CONSIDERABLY STRONGER AS COMPARED TO EARLY THIS MORNING. ALTHOUGH IT APPEARS UNLIKELY AT THIS TIME... IF BOUNDARY LAYER WIND SPEEDS DROP TO 5 KTS OR LESS OVERNIGHT... FOG WOULD BECOME MUCH MORE DENSE AND WIDESPREAD. 12Z MODEL GUIDANCE FCST SOUNDINGS AND LOW LEVEL RH PROGS SUGGEST THAT THE COLD FRONT WILL BRING A LOW CLOUD DECK INTO MKG BY AROUND 12Z MONDAY MORNING (CIGS 1.5 TO 2.5 KFT AGL). THIS LOW CLOUD DECK WILL CONTINUE TO ADVANCE ESE IMPACTING THE REST OF OUR TAF SITES BY 14Z-16Z MONDAY MORNING. THEREFORE MVFR CONDITIONS WILL CONTINUE AT ALL TAF SITES FROM DAYBREAK MONDAY THROUGH 18Z MONDAY. && .MARINE...(359 AM EST SUN NOV 8 2009) AS A WARM FRONT APPROACHES SE WINDS WILL PREVAIL TODAY. HOWEVER A WARM FRONT WILL BE PASSING THROUGH FROM SOUTH TO NORTH THIS EVENING AND WINDS WILL SWING AROUND TO THE SOUTH AND INCREASE OVERNIGHT. WAVES WILL BUILD AND WE MAY NEED A SMALL CRAFT ADVISORY AFTER MIDNIGHT. THIS MAY BE A FAIRLY SHORT DURATION EVENT HOWEVER. WINDS WILL LIGHTEN TOWARD MID DAY MONDAY AS A COLD FRONT SAGS IN. && .HYDROLOGY...(359 AM EST SUN NOV 8 2009) RAIN ACROSS THE NORTHERN HALF OF THE CWA SHOULD BE LESS THAN A TENTH OF AN INCH WITH THE LATE MONDAY THROUGH EARLY TUESDAY COLD FRONT. THE I-94 CORRIDOR MAY SEE UP TO A QUARTER INCH IN THIS SAME TIME FRAME. THIS SHOULD HAVE LITTLE IMPACT ON HYDRO. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS: JK SHORT TERM: JK MJS LONG TERM: MJS AVIATION: LAURENS MARINE: JK HYDROLOGY: JK