Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 180734
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
334 AM EDT SAT OCT 18 2014

.SYNOPSIS...
ISSUED AT 330 AM EDT SAT OCT 18 2014

COOLER AIR WILL CONTINUE TO MOVE INTO NORTHERN MICHIGAN
TODAY...BEHIND A COLD FRONT WELL TO OUR EAST. SHOWERS WILL GRADUALLY
DIMINISH TODAY...WITH WEAK HIGH PRESSURE ARRIVING TONIGHT. ANOTHER
SYSTEM WILL APPROACH FROM THE NORTHWEST...BRINGING RAIN SUNDAY NIGHT
AND MONDAY. DRY AND WARMER WEATHER WILL RETURN BY THE SECOND HALF OF
THE WORK WEEK.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 330 AM EDT SAT OCT 18 2014

...GUSTY WINDS BEGIN TO DIMINISH...

HIGH IMPACT WEATHER POTENTIAL: GUSTY WINDS, ESPECIALLY OVER THE
GREAT LAKES WHERE GALE FORCE GUSTS WILL BE EXPECTED.

PRIMARY FORECAST CHALLENGES: RAIN SHOWERS COMING TO AN END WITH A
PERIOD OF LAKE ENHANCEMENT

CURRENTLY, MAIN SFC AND 500 MB TROUGH IS THROUGH THE FORECAST AREA,
AND NOW TO THE SOUTH. THERE ARE SOME SMALL LAKE AGGREGATE TROUGHS
OVER THE REGION, BUT FOR THE MOST PART IT LOOKS LIKE THE MAIN SYSTEM
RAIN IS THROUGH THE REGION. HOWEVER, NOW WITH THE NORTH FLOW OVER
THE REGION, WE ARE BEGINNING TO PICK UP SOME LAKE EFFECT RAIN BANDS
OVER N MICHIGAN. 850 MB TEMPERATURES THIS MORNING ARE AROUND -3C
WHILE THE LAKE MICHIGAN WATER TEMPERATURES ARE AROUND 13C.

TODAY...WITH THE SFC AND 500 MB TROUGH TO MOVE TO THE EAST SLOWLY TO
DAY THE NORTH TO NNW FLOW OVER THE UPPER GREAT LAKES WILL CONTINUE.
HOWEVER, THE MOISTURE IS EXPECT TO THIN OUT AS THE EXTREMELY DRY AIR
MASS ASSOCIATED WITH THE RIDGING UPSTREAM, WILL BE PULLED INTO THE
UPPER GREAT LAKES THROUGH THE AFTERNOON. AS THIS DRIER AIR MOVES
INTO THE REGION (850-700 MB LAYER RH<20%) THE LAKE EFFECT RAIN
SHOULD COME TO AN END BY THE LATE AFTERNOON. IT IS POSSIBLE THAT
THERE WILL STILL BE SOME CLOUDS AND A SPRINKLE OR TWO, BUT THE MAIN
THREAT FOR RAIN SHOULD BE DON. WINDS WILL GRADUALLY DIMINISH THROUGH
THE AFTERNOON AS THE GRADIENT RELAXES.

TONIGHT...THE DRYING CONTINUES, ESPECIALLY AS THE 850 MB RIDGE AXIS
MOVES INTO THE UPPER GREAT LAKES. THE 1000-850 STREAMLINES SHOW A
VERY SHARP TROUGH OVER THE REGION WITH THE 850 MB TEMPERATURES
CLIMBING OVER NIGHT INTO THE LOWER SINGLE DIGITS THIS SHOULD SHUT
OFF THE INSTABILITY OVER THE LAKE SO THAT MOST CLOUDS THAT WERE LAKE
INDUCED SHOULD BEGIN TO ALSO DIMINISH OVERNIGHT.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 330 AM EDT SAT OCT 18 2014

HIGH IMPACT WEATHER POTENTIAL...MINIMAL.

THE UPPER TROF CURRENTLY OVERHEAD WILL APPROACH NEW ENGLAND ON
SUNDAY. OUR BREAK IN THE UNSETTLED WX WILL BE TEMPORARY...AS A
NORTHERN STREAM SHORTWAVE WILL AMPLIFY AS IT DIVES INTO THE LAKES
REGION ON MONDAY. AFTER RELATIVELY QUIET WX SUNDAY...POPS WILL
INCREASE AGAIN SUNDAY NIGHT INTO MONDAY. THOSE PRECIP CHANCES ARE
THE MAIN ISSUE.

SUNDAY...A SHORTWAVE RIDGE ALOFT WILL FLATTEN OUT AS IT CROSSES
LOWER MI AT MIDDAY. AT THE SURFACE...HIGH PRESSURE WILL MOVE SLOWLY
UP THE OHIO VALLEY. RIDGING WILL EXTEND NORTHWARD INTO MI IN THE
MORNING...WITH LOW-LEVEL RETURN FLOW IN THE AFTERNOON AS THE RIDGE
SLIDES EAST. MOST OF SUNDAY WILL BE DRY...THOUGH NW FLOW AREAS WILL
SEE LAKE-INDUCED STRATOCU...AND HIGH AND EVENTUALLY MID CLOUDS WILL
BE THICKENING THRU THE DAY. THE DEEPER AIRMASS IS OTHERWISE DRY
(850-700MB RH LESS THAN 10 PERCENT FOR THE 1ST HALF OF THE DAY).

HOWEVER...INCREASING WARM ADVECTION/ISENTROPIC ASCENT...AND THE
ARRIVAL OF AN 850MB WARM FRONT FROM THE WEST...WILL RESULT IN RAPID
THICKENING/LOWERING OF CLOUD COVER IN WESTERN SECTIONS VERY LATE.
THERE IS A LOT OF ANTECEDENT DRY AIR TO OVERCOME (PER PREVIOUS
PARAGRAPH)...BUT THE NAM/GFS/ECMWF ARE ALL INCLINED TO SPIT OUT A
TOUCH OF QPF IN PARTS OF NW LOWER AND WESTERN CHIP/MACK JUST BEFORE
00Z. SMALL CHANCE POPS ARE ALREADY IN WESTERN SECTIONS VERY
LATE...AND THIS STILL LOOKS MORE THAN REASONABLE.

MAX TEMPS WILL STILL BE COOL...RANGING THRU THE 40S.

SUN NIGHT/MONDAY...CLIPPER-ISH SURFACE LOW WILL DEEPEN AS IT REACHES
FAR NORTHERN LAKE MI BY MONDAY MORNING. IT WON/T BE IN A TREMENDOUS
HURRY...REACHING ONLY FAR SOUTHERN LAKE HURON BY LATE MONDAY. ALSO
BY MONDAY...THE SURFACE LOW IS ESSENTIALLY STACKED WITH THE DIGGING
500MB TROF. THE INITIAL WARM ADVECTION SURGE SUNDAY EVENING MOVES
QUICKLY EAST...AND IN NORTHERN LOWER MI THERE MAY BE A BIT OF BREAK
BEHIND IT BEFORE MORE WIDESPREAD -RA SPREADS BACK IN WITH THE
SURFACE LOW AND 500MB TROF. THAT/S A LOT OF DETAIL THOUGH FOR A 4TH
PERIOD FORECAST. WILL PORTRAY LIKELY POPS SPREADING W TO E AS SUNDAY
NIGHT PROCEEDS. BUT...WITH MODELS SLOWING SLIGHTLY AND HPC FAVORING
THE SLOWER GFS/ECMWF...WILL REMOVE ANY DECREASE IN POPS FROM W TO E
TOWARD MORNING. MONDAY MORNING WILL NEED LIKELY POPS NEAR/EAST OF
I-75 IN BOTH PENINSULAS. BY AFTERNOON...STILL A LOT OF DEEP CYCLONIC
FLOW...BUT WE ARE ALSO SEEING SUBTLE DRYING AS THE MID LEVEL TROF
MOVES JSUT EAST OF THE FORECAST AREA. A BLANKET CHANCY POP WILL DO
FINE.

MIN TEMPS UPPER 30S TO MID 40S. MAX TEMPS NEAR 50F TO THE MID 50S.

REST OF THE FORECAST...UPPER TROF WILL GRADUALLY CLOSE OFF AS IT
PROGRESSES TO THE MID-ATLANTIC COAST BY LATE WED. RIDGING WILL BUILD
INTO THE UPPER MS VALLEY AND EVENTUALLY THE WESTERN LAKES IN ITS
WAKE. A CHANCE OF -SRHA WILL LINGER ACROSS MUCH OF NORTHERN MI
MONDAY NIGHT...PERHAPS EVEN INTO TUE MORNING IN EASTERN SECTIONS.
BUT WE SHOULD SEE A FEW DAYS OF DRY AND WARMER WX FOR MID-WEEK AS
THE RIDGING ALOFT BUILDS IN. HIGHS SHOULD BE IN THE 50S EVERYWHERE
BY THU...AND WILL TOUCH 60F IN SOME OF THE WARMER LOCALES (LIKE
TVC). A SHORTWAVE TROF WILL MOVE ALONG THE US/CANADA BORDER AND BUTT
INTO THE SKINNY RIDGE...BUT THE MODELS DIFFER WIDELY AS TO HOW
STRONG THIS TROF IS AND HOW MUCH SUCCESS IT WOULD HAVE. THE ECMWF IS
MUCH LOWER AMPLITUDE THAN THE GFS...AND ALLOWS TO RIDGING TO HOLD ON
INTO THE START OF THE WEEKEND. WILL TREND THE FORECAST IN THIS
DIRECTION.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1145 PM EDT FRI OCT 17 2014

MAINLY MVFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF
SITES OVERNIGHT THRU SATURDAY MORNING AS WAVES OF RAIN SHOWERS
IMPACT THE AREA ON THE BACKSIDE OF DEPARTING LOW PRESSURE. PRECIP
WILL END BY AROUND MIDDAY...WITH DECREASING CLOUDS BY LATE
AFTERNOON/EVENING. WINDS WILL REMAIN FROM THE NW AT 15 TO 25 KTS
WITH A FEW HIGHER GUSTS POSSIBLE...DIMINISHING TO LESS THEN 10 KTS
AROUND SUNSET SATURDAY EVENING.


&&

.MARINE...
ISSUED AT 330 AM EDT SAT OCT 18 2014

GALE WARNINGS WILL CONTINUE THROUGH THE AFTERNOON AS THE WINDS
CONTINUE BLOWING AROUND 35 KNOTS. HOWEVER, AS NOTED IN THE SHORT
TERM SECTION, THE WINDS BEGIN TO FALL OFF PRETTY QUICKLY IN THE
AFTERNOON AS THE GRADIENT CONTINUES TO RELAX. TONIGHT THE WINDS
ALMOST GO CALM AS THE RIDGE AXIS MOVES THROUGH THE REGION. SUNDAY
THE WINDS WILL BACK TO THE SOUTHWEST AS THE RETURN FLOW BEGINS TO
AFFECT THE REGION FROM THE SFC HIGH MOVING TO THE EAST. HOWEVER,
WINDS WILL REMAIN AT 10 TO 15 KNOTS AT MOST AND DIMINISH AGAIN
SUNDAY NIGHT AS THE NEXT SYSTEM MOVES INTO THE REGION.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR LHZ346-349.
     GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR LHZ345-347-348.
LM...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR LMZ341.
     GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR LMZ323-342-344>346.
LS...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR LSZ322.
     GALE WARNING UNTIL NOON EDT TODAY FOR LSZ321.

&&

$$

SYNOPSIS...JZ
SHORT TERM...JL
LONG TERM...JZ
AVIATION...MR
MARINE...JL






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