Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 061735
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
135 PM EDT WED MAY 6 2015

.UPDATE...
ISSUED AT 120 PM EDT WED MAY 6 2015

CLOUDS ARE BEING EATEN AWAY FROM THE POCKET OF DRY AIR THAT HAS
BEEN SITTING OVER N MI THE LAST FEW DAYS. THE SFC DEWPOINTS HAVE
BEEN FALLING INTO THE LOWER TO MID 30S F OVER THE PAST FEW HOURS
NORTH OF M-32, BUT IT LOOKS LIKE THE MOISTURE ASSOCIATED WITH THE
WARM FRONT IS BEGINNING TO STABILIZE THE DEWPOINTS A BIT. HAVE
UPDATED THE TEMPERATURES AND RELATIVE HUMIDITY FOR THE AFTERNOON.

UPDATE ISSUED AT 1018 AM EDT WED MAY 6 2015

A WEAK WARM FRONT IS MOVING THROUGH THE FORECAST AREA, AND IS
ASSOCIATED WITH THE 500 MB RIDGE. ONCE THE RIDGE IS NORTH OF THE
FORECAST AREA, LATE THIS AFTERNOON, THE MID LEVEL MOISTURE WILL BE
OUT OF THE REGION, AND IT IS EXPECTED THAT WITH THE LACK OF
MOISTURE, THE CLOUDS BELOW THE 700-500 MB LAYER WILL BLOCK ENOUGH
OF THE HEATING TO KEEP THE SCATTERED RAIN FROM HAPPENING. OF
COURSE, THE LOW LEVEL DRY AIR IS ALSO HELPING IN THAT CAUSE. SO
HAVE LET THE FORECAST RIDE FOR THE TIME BEING. HOWEVER, A LITTLE
CONCERNED AT SOME OF OUR RH IDEAS SO WILL BE LOOKING INTO THAT A
LITTLE MORE OVER THE NEXT HOUR OR TWO.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 233 AM EDT WED MAY 6 2015

...MAYBE A LITTLE LIGHT RAIN?...

SYNOPTIC PATTERN AND OBSERVATIONS:

EARLY THIS MORNING...SFC HIGH PRESSURE IS OVERHEAD WITH LOTS OD
DRY AIR AROUND PER 00Z APX SOUNDING SHOWING PWATS OF 0.24". ONLY
SOME HIGHER LEVEL CLOUDS PASSING BY TO THE EAST...ASSOCIATED WITH
WEAK VORTICITY EJECTED FROM A SHORTWAVE OVER CO/NE/WY. A FAIRLY
TIGHT LOW LEVEL MOISTURE GRADIENT WAS ACROSS SRN LOWER
MICHIGAN...WHILE A MORE DEFINED FRONT IS DRAPED ACROSS CENTRAL
IL/SRN IN. LOW LEVEL CLOUDS WERE COMMON ACROSS SRN LOWER...AS WELL
AS SOME LIGHT RAINS ASSOCIATED WITH THAT WEAK VORTICITY AND WHAT
00Z REGIONAL RAOBS SUGGEST AS AN ELEVATED WARM FRONT. THERE WAS A
MINIMAL NORTHWARD DRIFT OF THESE CLOUDS/LIGHT RAINS.

SYNOPTIC PATTERN EVOLUTION AND ASSOCIATED WEATHER:

FOR THE MORNING HOURS...DATA SUGGESTING THAT THE LOW LEVEL
CLOUDS/DEEPER MOISTURE IS EXPECTED TO LIFT NORTH AND INTO THE M-55
CORRIDOR/POSSIBLY TVC. CONFIDENCE NOT HIGH WITH THIS IDEA...DUE TO
THE LARGE AMOUNT OF DRY AIR AROUND. COULD POSSIBLY SEE SOME
CONTINUED RADIATIONAL COOLING HELPING FIRE OFF SOME LOW CLOUDS
BRIEFLY THIS MORNING THOUGH. LESS CONFIDENCE IN SEEING SOME LIGHT
RAINS...AS EVEN THE RECENT WEAK ECHOES ALOFT ARE LIKELY
EVAPORATING INTO THE DRY AIR.

SOME SCT CUMULUS EXPECTED SOUTH OF M-72...WITH PERIODIC MID CLOUD
DRIFTING EASTWARD ACROSS THE REGION IN NRN LOWER. LESS CLOUD
ACROSS EASTERN UPPER WHERE THE AIR IS MUCH DRIER. MAYBE SOME OF
THIS CLOUD ARRIVING TONIGHT. MOISTURE NEVER REALLY GETS DEEP
ENOUGH FOR A BONA FIDE CHANCE FOR LIGHT RAINS....BUT CURRENT 30%
CHANCE ACROSS NRN LOWER CAN`T TOTALLY BE RULED OUT. BEST BET IS TO
PLAN ON A RAIN FREE DAY. AS THE SHORTWAVE TROUGH LIFTS NORTH INTO
THE UPPER MISSISSIPPI VALLEY TONIGHT...THE ELEVATED AND SFC BASED
WARM FRONTS BRING IN BETTER SFC/LOW LEVEL DEW POINTS. THE MID
LEVEL RIDGE GETS MORE ESTABLISHED OVER US...WITH ONLY SOME WEAK
DEEP LAYER WAA. DOUBT HIGHLY THAT LIGHT RAIN IS POSSIBLE...AND
WILL KEEP THE DRY FORECAST...BUT COULD SEE A BETTER CHANCE FOR
SOME LATE NIGHT STRATUS DEVELOPMENT IF WE CAN GET SOME DECENT
RADIATIONAL COOLING.

HIGHS IN THE 60S AND LOWER 70S TODAY...COOLER LAKESHORES. LOWS
TONIGHT IN THE MID 40S TO LOWER 50S.

&&

.SHORT TERM...(THURSDAY THROUGH FRIDAY NIGHT)
ISSUED AT 233 AM EDT WED MAY 6 2015

HIGH IMPACT WEATHER POTENTIAL: ELEVATED FIRE DANGER THURSDAY.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: DEEP SOUTHWEST FLOW WILL BE
WELL ESTABLISHED ACROSS THE WESTERN LAKES TO END THE WORK
WEEK...COURTESY OF DEEP WESTERN TROUGHING AND SLOW TO YIELD EASTERN
LAKES CENTERED RIDGING. WHOLE PATTERN SLOWLY SHIFTS EAST FRIDAY ON
INTO THE WEEKEND/START OF NEXT WEEK...EVENTUALLY ALLOWING UPSTREAM
MOISTURE PLUME AND BAROCLINIC AXIS TO BUILD INTO OUR AREA...AND
HOPEFULLY SETTING THE STAGE FOR SOME MUCH NEEDED RAINFALL.

PRIMARY FORECAST CONCERNS/CHALLENGES: ADDRESSING FIRE WEATHER
PARAMETERS (TEMPS/RH/WIND) THURSDAY AND LATE WEEK/WEEKEND SHOWER AND
STORM CHANCES.

DETAILS: BIGGEST STORY TO KICK OFF THE FORECAST IS THE RATHER WARM
WEATHER EXPECTED THURSDAY. STRENGTHENING SOUTH WINDS WILL DO THE
TRICK...WITH THERMAL PROGS CONTINUING TO SUPPORT HIGHS WELL INTO THE
70S...WITH EVEN A FEW SPOTS TOPPING 80 DEGREES IN NORTHEAST LOWER
(OFF COURSE..."COOLEST" READINGS IN EASTERN UPPER AND NEAR THE BIG
WATERS). SHOULD BE DRY...IGNORING SHOWER DEVELOPMENT ON SOME PROGS
VIA UNREALISTICALLY HIGH DEW POINTS. STILL PLENTY OF CONCERN FOR
ELEVATED FIRE WEATHER...WITH BOTH WINDS/TEMPS NEARING/EXCEEDING RED
FLAG CRITERIA. SLOWLY INCREASING LOW LEVEL MOISTURE WILL PARTIALLY
OFFSET THE WARM TEMPERATURES...LOOKING TO KEEP RH VALUES SAFELY
ABOVE CRITICAL LEVELS. THAT`S ABOUT THE ONLY GOOD NEWS...WITH
BACKGROUND VERY DRY SURFACE CONDITIONS AND WARM TEMPS/WINDS EASILY
SUPPORTING A CONTINUED MENTION OF ELEVATED FIRE DANGER IN OUR
HAZARDOUS WEATHER PRODUCTS.

SHORTWAVE TROUGH ADVANCES UP WESTERN FLANK OF RIDGING WELL OF TO OUR
WEST AND NORTHWEST THURSDAY AND THURSDAY NIGHT...WITH ITS ATTENDANT
COLD FRONT SLOWLY SAGGING EAST INTO THE FAR WESTERN LAKES THURSDAY
NIGHT. INDICATIONS THIS FRONT MAY BECOMING STATIONARY ACROSS THE
AREA AS IT PARALLELS MID LEVEL FLOW AND WAITS FOR ADDITIONAL ENERGY
TO EJECT OUT OF WESTERN TROUGH DURING THE WEEKEND. WHILE FORCING IS
NOT GREAT INITIALLY...SHARP THETA-E ADVECTION WITH EASTWARD MOVING
LOW LEVEL JET CORE SUPPORTS CHANCES FOR SHOWERS AND STORMS LATER
THURSDAY NIGHT INTO FRIDAY NIGHT. NOT LOOKING AT ANY SEVERE WEATHER
GIVEN LIMITED DEEP LAYER SHEAR.

&&

.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 233 AM EDT WED MAY 6 2015

WHILE CONFIDENCE REMAINS LOW WITH REGARDS TO SPECIFIC FRONTAL
PLACEMENT AND TIMING OF MID LEVEL SUPPORT...OVERALL PATTERN
REMAINS CONDUCIVE TO SOME DECENT RAIN POTENTIAL AS WIDE OPEN
WESTERN GULF PROPELS DEEP MOISTURE INTO THE REGION (PWAT VALUES
WELL OVER AN INCH). PLACEMENT OF SURFACE FRONT/TIMING OF
ADDITIONAL MID LEVEL IMPULSES WILL BE PARAMOUNT IN DETERMINING
WHERE THE GREATEST SHOWER THREAT WILL ALIGN. PLENTY OF GUIDANCE
UNCERTAINTY WITH REGARDS TO ABOVE...WITH THE GFS MORE PROGRESSIVE
WITH INITIAL FRONTAL MOVEMENT...ESSENTIALLY RESULTING IN A MOSTLY
DRY WEEKEND. OTHER MID RANGE PROGS NOT NEARLY AS
AGGRESSIVE...SETTING UP MULTIPLE ROUNDS OF SHOWERS AND STORMS
RIGHT THROUGH MONDAY. WHILE NON-GFS GUIDANCE IS USUALLY SUPERIOR
WITH SUCH PROGRESSION AND TIMING...GOTTA FEELING YET TO BE
RESOLVED CONVECTIVE COMPLEXES/ATTENDANT COLD POOLS WILL HAVE
PLENTY TO SAY ON EVENTUAL PLACEMENT OF THE ACTIVE BAROCLINIC AXIS.
PER THE USUAL AT THESE EXTENDED RANGES...BEST TO TAKE A CONSENSUS
BLEND APPROACH...WHICH... UNFORTUNATELY...RESULTS IN MULTIPLE
PERIODS OF CHANCE POPS RIGHT THROUGH TUESDAY. STAY TUNED...AS
PLENTY OF CHANGES MORE THAN EXPECTED DURING THE PERIOD...WITH
EVENTUAL BETTER TEMPORAL AND SPATIAL RESOLUTION NARROWING BEST
PERIODS FOR SHOWER/STORM POTENTIAL.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 120 PM EDT WED MAY 6 2015

POCKET OF DRY AIR ASSOCIATED WITH THE SFC HIGH IS BEGINNING TO MIX
OUT THE CLOUDS OVER THE REGION. HAS LEAD TO MUCH LESS IN THE WAY
OF MVFR CIGS TODAY, WHICH WILL CONTINUE INTO THE EVENING. HOWEVER,
THE MOISTURE TO THE WEST IS BEGINNING TO PUSH INTO THE REGION, AND
WITH THE LIGHT WINDS EXPECTED OVERNIGHT, LOW CLOUDS (IFR CIGS) ARE
EXPECTED DURING THE EARLY MORNING HOURS (MAINLY AFTER 08Z). THIS
WILL LAST INTO THE MID MORNING, ONCE THE SUN HAS BEGUN THE MIXING
PROCESS, AND THE SKY WILL GO BACK TO VFR CONDITIONS AGAIN.

&&

.MARINE...
ISSUED AT 233 AM EDT WED MAY 6 2015

VERY STABLE CONDITIONS OVER THE GREAT LAKES WITH SFC HIGH PRESSURE
IMPLANTED IN THE REGION. THIS HIGH PRESSURE WILL BE SLOW TO
EXIT...BUT A TIGHTER PRESSURE GRADIENT SETS UP ACROSS LAKE
MICHIGAN LATE TONIGHT INTO THURSDAY...AHEAD OF LOW PRESSURE
WORKING INTO ONTARIO.

WINDS WILL BE LESS THAN 10KTS OUT OF THE EAST....TENDING TO TURN
ONSHORE THIS AFTERNOON. WINDS REMAIN LIGHT TONIGHT...WHILE TURNING
OUT OF THE SOUTH. SOME INCREASE IN WINDS THURSDAY...BUT HIGH
DEGREE OF STABILITY KEEPING WINDS BELOW ADVISORY LEVELS. THIS SAME
THOUGHT CONTINUES INTO THURSDAY NIGHT...BUT A GREATER THREAT IS
THERE FOR ADVISORY LEVEL WINDS.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...JSL
NEAR TERM...SMD
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JSL
MARINE...SMD


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