Forecast Discussions mentioning "ACARS", "MDCRS", or "AIRCRAFT" received at FSL on 01/31/02

...WINTER STORM CONTINUES TO AFFECT SOUTHEAST MICHIGAN...

THE SURGE OF MOISTURE INTO THE LOWER GREAT LAKES AHEAD OF THE SURFACE LOW OVER SOUTHERN MISSOURI IS PROVIDING HEAVY WINTER PRECIP TO SOUTHERN LOWER MICHIGAN. FRONTOGENETICAL FORCING WITHIN ENTRANCE REGION OF UPPER JET TO THE NORTH...STRONG ISENTROPIC ASCENT OVER LOWER MICHIGAN AND PLENTY OF MOISTURE TRANSPORT NORTH OF THE ARCTIC FRONTAL BOUNDARY IN THE OHIO RIVER VALLEY WILL CONTINUE HEAVY PRECIP THROUGH THE MORNING.

I WILL CONTINUE WITH CURRENT WARNINGS AND ADVISORIES THROUGH THIS AFTERNOON. THE MESO ETA SOLUTION IS SHOWING VERY STRONG 850-700MB FRONTOGENETICAL FORCING MOVING ACROSS SOUTHEAST MICHIGAN BETWEEN 09Z AND 15Z THIS MORNING. THIS...COUPLED WITH STRONG 295K ISENTROPIC ASCENT AND DEEP MOISTURE WILL CONTINUE THE PRECIPITATION THROUGH THIS MORNING. CURRENT AREA RADAR MOSAIC SUPPORTS THIS AS PRECIPITATION EXTENDS ALL THE WAY BACK INTO THE MID MISSISSIPPI RIVER VALLEY. BIG QUESTION FOR THE REMAINDER OF THIS STORM SYSTEM IS HOW MUCH ADDITIONAL SNOWFALL WILL OCCUR AND WHEN SNOWFALL WILL BEGIN TO SWITCH OVER TO FREEZING RAIN. THROUGH MUCH OF THE OVERNIGHT HOURS LENAWEE AND MONROE COUNTIES HAVE REPORTED SLEET...WHILE SURFACE OBS ACROSS NORTHERN INDIANA/OHIO ARE REPORTING FREEZING RAIN. PRECIP TYPE FROM MESO ETA MODEL SOUNDINGS ARE LINING UP WELL CURRENT OBS AND LATEST ACARS SOUNDING. SOUNDING ANALYSIS SHOWS DRAMATIC WARMING ALOFT OCCURRING FROM SOUTH TO NORTH THIS MORNING AS STRONG MID LEVEL WARM AIR ADVECTION OCCURS. THE LATEST PROFILER DATA SHOWS THE WINDS AT 700MB HAVE ALREADY VEERED TO THE SOUTHWEST (AND INCREASED TO 50 KNOTS). FROM SOUNDING ANALYSIS...SNOW SHOULD SWITCH OVER TO SLEET AND THEN FREEZING RAIN QUITE QUICKLY. DETROIT SHOULD SWITCH OVER TO FREEZING RAIN AROUND 12Z...FLINT BY 18Z...WHILE SAGINAW SWITCHES TO SLEET AROUND 20Z. THUS FOR THIS MORNING ICE WILL BE HIT UPON HARDER FROM DETROIT-ANN ARBOR SOUTH. A LATER CHANGE OVER FARTHER NORTH WILL SPELL ADDITIONAL ACCUMULATIONS. WITH STRONG FORCING CONTINUING THROUGH 15Z...295K SPECIFIC HUMIDITIES AROUND 4(G/KG)...WILL ADD AN ADDITIONAL 3 TO 5 INCHES. MAY BOOST THESE AMOUNTS UP A BIT ALONG M-59...WHERE STRONGER FRONTOGENETICAL FORCING WILL LEAD TO SOME HEAVIER BURSTS OF SNOWFALL. BASED ON REPORTS OF UP TO 3 INCHES THAT HAVE ALREADY FALLEN IN SAGINAW AND TUSCOLA COUNTIES...I WILL BUMP THE CURRENT ADVISORY TO A WARNING.

THIS AFTERNOON WE WILL GET A BREAK IN THE PRECIPITATION AS THE SURFACE WAVE AND UPPER JET PULL NORTHEAST. MID LEVEL MOISTURE ALSO GETS STRIPPED AWAY. I WILL THUS TAPER PRECIP TO FREEZING DRIZZLE DURING THE AFTERNOON. TONIGHT...THE NEXT LOW WILL MOVE INTO THE OHIO VALLEY AHEAD OF A PROGRESSIVE UPPER TROUGH. SOME TIMING DIFFERENCES AMONG THE ETA AND AVN...WITH THE AVN BEING A LITTLE FASTER. WILL TEND TO LEAN TOWARDS THE FASTER SOLUTION GIVEN THE FAST CONFLUENT FLOW ALOFT. THUS AFTER A PERIOD OF FREEZING DRIZZLE...PRECIP WILL MOVE BACK INTO THE FAR SOUTHERN COUNTIES (ALONG AND SOUTH OF I-94) DURING THE EVENING. ALL MODELS ARE SHOWING RELATIVELY HIGH QPFS IN THIS AREA...WITH THE ETA SHOWING 12HR AMOUNTS BETWEEN A HALF AN INCH AND AN INCH. DEEP WARM LAYER WITH MAX TEMPS NEAR +10C WILL LEAD TO RAIN. TEMPS AT THE SURFACE WILL BE PROBLEMATIC. GIVEN CONTINUING NORTHEAST WINDS...TENDING TO FOLLOW THE MESO ETA SURFACE TEMPS WHICH REMAIN AT AND SLIGHTLY BELOW FREEZING THROUGH THE NIGHT. THIS WILL SPELL ANOTHER ROUND OF FREEZING RAIN FOR THE SOUTHEASTERN COUNTIES. FOR THIS REASON...I WILL KEEP THE WINTER STORM WARNING UP FOR DETROIT SOUTH THROUGH TONIGHT. MOISTURE WANES CONSIDERABLE FOR THE REST OF THE FORECAST AREA...MODELS ACTUALLY POINT TO A WEDGE OF DRY MID LEVEL AIR ADVECTING INTO THE NORTHERN COUNTIES OVERNIGHT. WITH SOME LACK OF MID LEVEL MOISTURE THROUGH SOME OF THE PERIOD AND WITH WARM LAYER PUSHING ALL THE WAY TO SAGINAW BAY...I WILL KEEP PRECIP AS LIGHT FREEZING RAIN AND SLEET IN THE NORTH.

ON FRIDAY...COLD AIR ADVECTION BEGINS ON THE BACK SIDE OF THE SURFACE LOW. SOME MID LEVEL DEFORMATION PASSES TO THE NORTH...BUT MODELS SHOW THIS FEATURE WEAKENING AS 500MB TROUGH WEAKENS. I WILL CONTINUE TO MENTION LIKELY POPS FOR SNOW IN THE NORTH WITH DEFORMATION/WRAP AROUND MOISTURE/CHANCE POPS IN THE SOUTH.

.DTX...WINTER WEATHER ADVISORY...TODAY...MIZ047>049- WINTER STORM WARNING...TODAY...MIZ053>055-060>063-068>070 WINTER STORM WARNING...TODAY AND TONIGHT...MIZ075-076-082-083

CONSIDINE



BASED ON NEW SOUNDING AND ACARS DATA...TOO MUCH WARM AIR IN LOWER LEVELS FOR MUCH FROZEN PRECIP. MAY GET MORE FZRA ACROSS THE ADVISORY THAN PREVIOUSLY THOUGHT THIS MORNING.

NEW ZONES COMING SOON.

PW

...PREVIOUS DIS BELOW....

DESPITE MINOR DIFFERENCES IN THE MODELS REGARDING STORM TRACK AND INTENSITY...ALL OPERATIONAL MODELS AGREE THAT THE BULK OF PRECIP STAYS TO OUR NORTH AND NORTHWEST THROUGH THE DAY TODAY IN BEST LOW LEVEL WAA.

THIS WILL BE HARD TO WORD THIS AM...BUT PRECIP SHOULD BE LIGHT AND INTERMITTENT. AS FOR TYPE...IT LOOKS LIKE EARLY THIS MORNING IF ANY PRECIP IS OCCURRING IT WILL BE RAIN NEAR THE COAST WHERE ADVISORIES ARE NOT UP. THERE MAY BE ENOUGH LOW LEVEL COLD AIR (H950 -2) TO WARRANT SLEET MENTION EARLY ON...THEN ALL RAIN. IN TRANSITIONAL ZONES...A SLEET TO RAIN/SLEET MIX FOR AWHILE LONGER BEFORE TOTAL CHANGE OVER TO RAIN SOMETIME TONIGHT. MAY KEEP SOME MENTION OF FREEZING RAIN IN THERE AS IT WILL BE CLOSE. WELL NORTH AND WEST...EXPECT SNOW AND SLEET...THEN GRADUAL CHANGE TO FREEZING RAIN LATE IN DAY. AGAIN...PRECIP SHOULD BE LIGHT AND NOT STEADY THROUGHOUT. WILL NOT INCLUDE ANY APPRECIABLE SNOW ACCUMULATIONS.

BY TONIGHT...ANY PRECIP SHOULD BE PREDOMINATELY RAIN AND WILL BE AGAIN VERY LIGHT AS SFC WARM FRONT NEARS. INLAND WILL KEEP FZRA MENTIONED AS SFC TEMPS WILL BE CLOSE. TEMPS STEADY OVERNIGHT.

BY FRIDAY...WARM FRONT JUMPS TO THE NORTH AND THINK WE ARE DRY IN THE MORNING. MAY GET SOME SHOWERS DURING THE AFTERNOON WITH COLD FRONT. TEMPS LOOK TO SHOOT UP DESPITE PLENTY OF LOW LEVEL MOISTURE AND THUS CLOUDS TRAPPED UNDERNEATH INVERSION. GUIDANCE NUMBERS SHOW THIS WARM AIR WITH MID 50S INLAND TO LOWER TO MID 60S NEAR THE COAST. ETA 2M TEMPS SIMILAR.

WINDY ON THE BACK SIDE OF THIS FRONT WITH PLENTY OF CAA FOR SAT. WILL NOT CHANGE MUCH IN THE EXTENDED ATTM. MARINE...SCA UP FOR TODAY. WILL KEEP MENTION OF TIDES IN MARINE...BUT GUIDANCE NUMBERS SLIGHTLY LOWER THIS RUN AS COMPARED TO 12Z NUMBERS. THINK ANY MINOR FLOODING VERY ISOLATED AT BEST.

PACKAGE OUT A LITTLE LATE TONIGHT.

COOR WITH BOX.

.OKX... CT...WINTER WX ADV FOR CTZ005>008. NJ...WINTER WX ADV FOR NJZ002>004. NY...WINTER WX ADV FOR NYZ067>071. MARINE...SCA FOR ALL WTRS...ANZ350-353-355-330-335-338.

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