FXUS63 KAPX 120452
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1150 PM EST FRI DEC 11 2009
.SYNOPSIS.../ISSUED AT 400 PM/
COLD AIR FUNNELING ACROSS THE GREAT LAKES WILL CONTINUE TO PRODUCE
LAKE EFFECT SNOW SHOWERS THROUGH TONIGHT BEFORE COMING TO AN END
EARLY SATURDAY MORNING. HIGH PRESSURE WILL TEMPORARILY BUILD INTO
THE STATE ON SATURDAY WITH SLIGHTLY MILDER AIR RETURNING TO NORTHERN
MICHIGAN. HOWEVER...THIS PUSH OF WARMER AIR WILL ALSO RESULT IN A
RENEWED CHANCE FOR MORE WIDESPREAD LIGHT SNOW FOR THE LATTER HALF OF
THE WEEKEND...WITH SEVERAL ADDITIONAL CHANCES FOR SNOW THROUGH THE
FIRST HALF OF THE COMING WORK WEEK. THEREAFTER...IT APPEARS
INCREASINGLY LIKELY ANOTHER SURGE OF ARCTIC AIR AND PLENTIFUL LAKE
EFFECT SNOWS WILL MAKE AN APPEARANCE FOR THE MIDDLE OF NEXT WEEK.
&&
.SHORT TERM.../ISSUED AT 1021 PM/...OVERNIGHT
SURFACE RIDGING CONTINUES TO BUILD INTO THE WRN GREAT LAKES REGION
LATE THIS EVENING...WITH THE RIDGE AXIS JUST UPSTREAM OF MICHIGAN
ATTM. REMNANTS OF DYING LAKE EFFECT EVENT CONTINUE TO SHOW A GRADUAL
DOWNWARD TREND IN BOTH AREA COVERAGE AND INTENSITY THIS EVENING.
LAKE BANDS HAVE SHIFTED BACK AROUND TO A STRAIGHT WEST/EAST
ORIENTATION AFTER A BRIEF SHIFT TO A W/SW TRAJECTORY DURING THE DAY
AS A WEAK WAVE MOVED THRU THE REGION. RESIDUAL SNOWFALL WITHIN THESE
BANDS ARE GENERALLY LIGHT...WITH RADAR ESTIMATES OF SNOWFALL SO FAR
THIS EVENING MAINLY AROUND AN INCH OR LESS. SKIES ACROSS INTERIOR
SECTIONS OF NRN LWR MICHIGAN SOUTH OF M-32 HAVE BECOME MAINLY
CLEAR...WITH ONLY LAKE-INDUCED CLOUD COVER REMAINING ACROSS OUR CWA.
WINDS ARE DIMINISHING ...BUT ARE STAYING SUFFICIENTLY STRONG TO
PRECLUDE TEMPS FROM PLUMMETING...EVEN IN AREAS THAT HAVE CLEARED.
SURFACE RIDGE AXIS WILL MOVE OVERHEAD DURING THE BALANCE OF THE
NIGHT...SHIFTING JUST EAST OF OUR CWA BY DAYBREAK. LOW LEVEL FLOW
WILL GRADUALLY BACK TO THE SW ON THE BACKSIDE OF THE RIDGE AXIS...
REDIRECTING ANY REMAINING LAKE SNOW BANDS INTO THE TIP OF THE MIT
AND THE STRAITS AREA. CURRENT FORECAST HANDLES THIS SCENARIO
NICELY...AND WILL NEED TO MAKE NO ADJUSTMENTS AT THIS TIME. TEMP
FORECAST IS ALSO ON TARGET...WITH OVERNIGHT LOWS RANGING FROM AROUND
10 DEGREES UNDER PERSISTENT LAKE CLOUDS ALONG THE LAKE MICHIGAN
SHORELINE TO AROUND ZERO IN NORTH CENTRAL AND NE LOWER MICHIGAN AWAY
FROM LAKE CLOUD INFLUENCES.
&&
.LONG TERM.../ISSUED AT 400 PM/...SATURDAY AND BEYOND
SATURDAY THROUGH NEXT FRIDAY...IT LOOKS LIKE WE WILL FINALLY CATCH A
BREAK FROM THE HEAVY LAKE EFFECT FOR A COUPLE OF DAYS DUE TO A
MILDER SOUTHWEST FLOW OVER THE WEEKEND. STILL SOME LINGERING
SOUTHWEST FLOW LAKE EFFECT ON SATURDAY. THEN THERE WILL BE GOOD
CHANCES FOR WARM ADVECTION LIGHT SNOW SATURDAY NIGHT INTO SUNDAY
MORNING AND ANOTHER GOOD CHANCE FOR LIGHT SNOW MONDAY AS A FAST
MOVING AREA OF LOW PRESSURE MOVES THROUGH. NORTHWEST FLOW LAKE
EFFECT THEN LOOKS LIKE A GOOD BET TUE INTO WED AS ANOTHER SHOT OF
ARCTIC AIR PLUNGES DOWN FROM THE NORTHWEST. WE MAY ROUND OUT NEXT
WEEK ON THE QUIETER SIDE AS RIDGING BUILDS IN FROM THE WEST LEADING
TO MODERATING TEMPERATURES...ALTHOUGH A SHORT WAVE DROPPING DOWN
FROM THE NORTHWEST MAY SPOIL THAT IDEA.
SATURDAY...SOME MINOR LAKE EFFECT MAY LINGER AS THE FLOW BACKS FROM
SOUTHWEST TO SOUTH SOUTHWEST. INCREASINGLY WARMER 850 MB
TEMPERATURES THROUGH THE DAY WILL LEAD TO WANING OVER LAKE
INSTABILITY...LIKELY SHUTTING OFF ACTIVITY ACROSS SOUTHWESTERN ZONES
(PLUS MOISTURE IS RATHER SLIM WITH MEAN 1000-850 MB RH ONLY 30 TO 40
PERCENT). OTHERWISE MILDER TEMPERATURES WITH HIGHS IN THE UPPER 20S
TO LOWER 30S.
SATURDAY NIGHT INTO SUNDAY MORNING...A WEAK SHORT WAVE EVIDENT ON
WATER VAPOR LOOP NEAR THE FOUR CORNER REGION WILL LEAD TO
WAA/ISENTROPIC ASCENT LIKELY BRINGING LIGHT SNOW TO THE AREA (AN
INCH OR TWO?) WITH MAYBE SOME SHALLOW LAKE HELP (CONTINUED MARGINAL
850 MB TEMPERATURES).
SUNDAY AFTERNOON AND NIGHT...NOT A WHOLE LOT LOOKS TO BE GOING ON
WITH SHORT WAVE RIDGING THE THEME SHUTTING OFF ANY LINGERING LIGHT
SNOW. THE POSSIBLE EXCEPTION TO THIS IS THAT IT MAY BE JUST COLD
ENOUGH FOR A BIT OF LIGHT LAKE EFFECT ACROSS NORTHERN CHIPPEWA
COUNTY. HIGHS IN THE MILDER LOWER TO MIDDLE 30S. LOWS RANGING FROM
THE UPPER TEENS TO MIDDLE 20S.
MONDAY...ENERGY CURRENTLY EVIDENT ON WATER VAPOR IMAGERY OFF THE
WEST COAST WILL LIKELY BRING THE AREA A PERIOD OF MAINLY LIGHT SNOW.
MILDER WITH HIGHS RANGING FROM THE UPPER 20S TO MIDDLE 30S.
TUESDAY AND WEDNESDAY...ANOTHER SHOT OF ARCTIC AIR WITH 850 MB
TEMPERATURES SHOWN TO BOTTOM OUT IN THE -20 C RANGE EXPECTED TO LEAD
TO A NORTHWEST FLOW LAKE EFFECT EVENT. WILL ADD THE POSSIBILITY
OF SIGNIFICANT SNOWFALL ACCUMULATIONS ACROSS PORTIONS OF NORTHWEST LOWER
AND EASTERN UPPER INTO THE HAZARDOUS WEATHER OUTLOOK. COLDER WITH
HIGHS ONLY RANGING FROM THE MIDDLE TEENS TO THE MIDDLE 20S AND
LOWS IN THE SINGLE DIGITS.
THURSDAY AND FRIDAY...HEIGHTS GENERALLY SPEAKING ARE SHOWN TO BE ON
THE RISE. HOWEVER...A SHORT WAVE MOVING THROUGH THE FLOW WILL BRING
A CHANCE OF SNOW SHOWERS FOR FRIDAY. NOT QUITE AS COLD WITH HIGHS IN
THE 20S.
SULLIVAN
&&
.MARINE.../ISSUED AT 400 PM/
SMALL CRAFT ADVISORY CRITERIA WINDS/WAVES EXPECTED TONIGHT THROUGH
AT LEAST EARLY SATURDAY NIGHT AS A BRISK SOUTHWEST WIND FLOW
PREVAILS. WINDS ARE THEN EXPECTED TO DIMINISH SOMEWHAT OVERNIGHT
SATURDAY INTO SUNDAY. IT IS TO CLOSE TO CALL WHETHER OR NOT SMALL
CRAFTS WILL NEED TO BE EXTENDED. LAKE EFFECT SNOW SHOWERS WILL
WANE LATER TONIGHT INTO SATURDAY WITH A BIT OF LIGHT SNOW LIKELY
SATURDAY NIGHT INTO SUNDAY MORNING.
AJS
&&
.AVIATION.../ISSUED AT 1150 PM/...VALID FOR 06Z TAFS
RESIDUAL LAKE EFFECT SNOW SHOWERS AND ACCOMPANYING MVFR VSBYS AND
CIGS WILL CONCENTRATE AROUND PLN OVERNIGHT...BEFORE DIMINISHING TO
FLURRIES ON SATURDAY. TVC WILL SEE SOME SCATTERED LIGHT SNOW
SHOWERS...WHILE APN REMAINS FREE FROM SNOW SHOWERS FOR THE NEXT 24
HRS...WITH VFR CONDITIONS EXPECTED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EST SATURDAY FOR LMZ323-341-342-
344>346.
LH...SMALL CRAFT ADVISORY UNTIL 11 PM EST SATURDAY FOR LHZ345>349.
LS...SMALL CRAFT ADVISORY UNTIL 11 PM EST SATURDAY FOR LSZ321-322.
&&
$$
