FXUS63 KAPX 021624
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1124 AM EST WED DEC 2 2009
.SYNOPSIS.../ISSUED AT 418 AM/
WEAK LOW PRESSURE WILL MOVE THROUGH THE REGION TODAY...BRINGING SOME
CLOUD COVER TO THE REGION...AND POSSIBLY SOME DRIZZLE EARLY ON. BUT
OVERALL...EXPECT ANOTHER QUIET WEATHER DAY WITH HIGH TEMPERATURES IN
THE 40S. SNOW SHOWERS WILL BECOME DOMINATE OVER THE NORTHERN LAKES
THURSDAY THROUGH THE WEEKEND...A STRONG STORM SYSTEM LIFTS FROM THE
GULF INTO NEW ENGLAND...PULLING SIGNIFICANTLY COLDER AIR INTO THE
REGION.
ADAM
&&
.SHORT TERM.../ISSUED AT 1124 AM/...THIS AFTERNOON
THE COLD FRONT IS PUSHING THROUGH THE E UPPER AND NW LOWER. THIS
HAS BEEN PRODUCING A BRIEF PERIOD OF FOG. WINDS GENERALLY HAVE
BEEN LOWER THAN EXPECTED WITH THE SYSTEM COMING THROUGH, SO HAVE
AT THIS POINT DROPPED THE SCA OVER N LAKE MICHIGAN. OTHERWISE, THE
TEMPERATURES LOOK ON TRACK. CLOUDS ARE A LITTLE THICKER THAN
EXPECTED, SO HAVE BEEFED UP THE CLOUDS FOR THE AFTERNOON. THE MAIN
QUESTION WILL BE WHAT WE GET WITH THE SYSTEM TONIGHT.
JSL
&&
.LONG TERM.../ISSUED AT 418 AM/...TONIGHT AND BEYOND
TONIGHT...DESPITE BETTER UPPER AIR SAMPLING OF SOUTHERN WAVE...STILL
SOME MODEL DISCREPANCIES...BOTH WITH REGARDS TO EXACT TRACK AND
TIMING. COMPARING WATER VAPOR/RADAR IMAGERY AND UPPER AIR SOUNDINGS
WITH MODEL FIRST GUESS FIELDS...CAN FIND NO GLARING INITIALIZATION
ERRORS. THUS...FORECAST WILL REMAIN SLANTED TOWARD ROCK-STEADY
ECMWF SOLUTION...WHICH HAS HELD FIRM IN DEPICTING LOW PRESSURE
MOVING JUST WEST OF THE APPALACHIAN MOUNTAIN CHAIN...WITH NORTHWEST
EXTENT OF TROWEL/DEFORMATION DRIVEN PRECIPITATION SHIELD ARCHING
BACK INTO NORTHERN LOWER MICHIGAN (HEAVIEST PRECIPITATION SHOULD
REMAIN OFF TO OUR SOUTHEAST). STILL...LIKE PREVIOUS FORECASTERS GRID
MANIPULATIONS...ACCOUNTING FOR TYPICAL FURTHER NORTHWEST PROPAGATION TO
PRECIPITATION SHIELD. THUS...HAVE ESSENTIALLY LEFT INHERITED GRIDS
ALONE...FEATURING LIKELY/CATEGORICAL WORDING FAR SOUTHEAST...
TAPERING POPS OFF TO THE NORTHWEST. THERMAL FIELDS CONTINUE TO
SUPPORT EVENING RAIN/SNOW MIXTURE ACROSS THE NORTHWEST...WITH
PREDOMINATELY ALL RAIN SOUTHEAST OF A LINE EXTENDING FROM HOUGHTON
LAKE TO PRESQUE ISLE. LATE NIGHT STRENGTHENING CAA ON INCREASINGLY
GUSTY NORTH WINDS SHOULD ALLOW PRECIPITATION TO TRANSITION OVER TO
ALL SNOW. HOWEVER...AMOUNTS SHOULD REMAIN MINIMAL (AROUND AN INCH OR
LESS EAST OF I-75) GIVEN COMBINATION OF LOW SNOW TO LIQUID RATIOS
(10 TO 1 OR LESS) AND LIGHT PRECIPITATION AMOUNTS.
THURSDAY AND THURSDAY NIGHT...WHAT'S LEFT OF SYNOPTIC DRIVEN SNOW
SHIELD WILL PULL OFF TO THE NORTHEAST DURING THE MORNING
THURSDAY...ALLOWING LAKE PROCESSES TO TAKE CENTER STAGE. WHILE
INSTABILITY LEVELS INCREASE TO MODERATE LEVELS BY AFTERNOON AS DELTA
T/S PUSH THE UPPER TEENS...STEADILY BACKING WIND FIELD FROM NORTH TO
NORTHWEST...SUB 800MB INVERSION LEVELS...INITIAL LACK OF GOOD
SYNOPTIC SCALE MOISTURE OVER THE WESTERN LAKES...AND TYPICAL EARLY
SEASON DIURNAL DISRUPTION SHOULD KEEP LAKE INDUCED SNOW SHOWER
INTENSITY AND ORGANIZATION IN CHECK. THAT BEGINS TO CHANGE THURSDAY
NIGHT AS MOISTURE AND INVERSION LEVELS INCREASE SUBSTANTIALLY
(EQUILIBRIUM LEVELS PER BUFKIT DATA PUSH 15KFT BY MORNING)...SENDING
LAKE INDUCED CAPE TO NEAR 700MB. STILL COME CAVEATS FOR SIGNIFICANT
ACCUMULATION...HOWEVER...SPECIFICALLY MAINTENANCE OF STEADILY
BACKING WIND FIELDS TO A WEST DIRECTION BY FRIDAY MORNING...ALLOWING
ANY GOOD BANDING STRUCTURES TO BE TRANSIENT. FOR THIS REASON...DO
NOT FORESEE ANY WARNING TYPE SNOWFALL AMOUNTS...BUT 2 TO 5 INCHES
NOT OUT OF THE QUESTION...ESPECIALLY IN FAVORED WEST NORTHWEST TO
WEST FLOW AREAS OF NORTHWEST LOWER MICHIGAN AND NEAR WHITEFISH POINT
IN EASTERN UPPER.
FRIDAY AND BEYOND...LAKE EFFECT CONCERNS REMAIN FRONT AND CENTER
THROUGH AT LEAST THE BEGINNING OF THE WEEKEND. PARAMETERS REMAIN RATHER
IDEAL THROUGH SATURDAY AFTERNOON...WITH 850MB TEMPERATURES RANGING
FROM -12C TO -15C (CORRESPONDING DELTA T/S IN THE HIGH TEENS TO NEAR
20)...DEEP MOISTURE...AND LAKE INDUCED EQUILIBRIUM LEVELS AROUND
15KFT. AND...UNLIKE THURSDAY NIGHT...FLOW LOOKS TO STABILIZE TO A
MORE WSW TO SW DIRECTION...REALLY TARGETING THE TIP OF THE MITT AND
SOUTHEAST UPPER MICHIGAN. TOO EARLY FOR ANY TYPE OF HEADLINES...BUT
LIKELIHOOD INCREASING THAT ONE WILL BE NEEDED IN SUBSEQUENT FORECAST
SHIFTS. WILL CONTINUE TO HIGHLIGHT THIS POTENTIAL IN EARLY MORNING
RENDITION OF THE HAZARDOUS WEATHER OUTLOOK. LAKE MORPHOLOGY
QUESTIONS INCREASE LATER IN THE WEEKEND AS EXACT WIND FLOW
DIRECTIONS REMAIN UNCERTAIN. STILL...GENERAL THEME OF LAKE EFFECT
SNOW SHOWERS IMPACTING NORTHWEST LOWER AND EASTERN UPPER SNOWBELTS
REMAINS UNCHANGED...WITH NO CHANGE FORTHCOMING TO INHERITED GRIDS
DURING THIS TIME.
MSB
&&
.MARINE.../ISSUED AT 1124 AM/
THE COLD FRONT IS PUSHING THROUGH THE E UPPER AND NW LOWER. THIS
HAS BEEN PRODUCING A BRIEF PERIOD OF FOG. WINDS GENERALLY HAVE
BEEN LOWER THAN EXPECTED WITH THE SYSTEM COMING THROUGH, SO HAVE
AT THIS POINT DROPPED THE SCA OVER N LAKE MICHIGAN.
JSL
&&
.AVIATION.../ISSUED AT 650 AM/...VALID FOR 12Z TAFS
TOP-DOWN SATURATION WILL LEAD TO GRADUALLY THICKENING
HIGH TO MID LEVEL CLOUD DECK TODAY. WILL HAVE TO CLOSELY WATCH FOR
SOME MORNING STRATUS FORMATION NEAR KPLN...AND POSSIBLY KTVC...AS
WEAKENING COLD FRONT APPROACHES. STRONG STORM SYSTEM PASSING
SOUTHEAST OF THE AREA TONIGHT WILL CONTINUE TO LOWER THE CLOUD DECK
TO MVFR TERRITORY. VIS RESTRICTING RAIN AND MIST LATE THIS EVENING
AT KAPN WILL TRANSITION TO SNOW AFTER MIDNIGHT. NOT SURE HOW MUCH OF
THIS WILL AFFECT KTVC AND KPLN. WILL LOWER CIGS TO MVFR CATEGORY...
BUT KEEP PRECIPITATION OUT OF THE TAFS AT THIS TIME. WINDS TO
INCREASE OUT OF THE NORTH TONIGHT...OCCASIONALLY GUSTY.
MSB
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
