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000
FXUS63 KMQT 142023
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
423 PM EDT TUE MAY 14 2013

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 422 PM EDT TUE MAY 14 2013

WV IMAGERY AND RUC ANALYSIS INDICATED A ZONAL MID/UPPER LEVEL
PATTERN ACROSS THE NRN CONUS WITH A PROMINENT SHORTWAVE TROUGH NEAR
WINNIPEG. AT THE SFC...A 992 MB LOW WAS ALSO LOCATED OVER SE
MANITOBA WITH A COLD FRONT THROUGH NW MN INTO ERN SD. A WARM FRONT
STRETCHED FROM CNTRL MN INTO SRN WI. RADAR INDICATED WEAK RETURNS
WITH VERY LIGHT SHOWERS(VIRGA OR SPRINKLES) THROUGH CNTRL UPPER MI
AS THE BAND OF 310K (750-600 MB)ISENTROPIC LIFT MOVES THROUGH THE
AREA. SATELLITE SHOWED SKIES CLEARING OVER THE WEST AS DRIER AIR
BEHIND THE PCPN BAND MOVES IN.

TONIGHT...MODELS SUGGEST THAT AS THE MID LEVEL SHRTWV TROUGH AND
ASSOCIATED SFC TROUGH MOVES THROUGH UPPER MI SOME SHOWERS MAY
DEVELOP...MAINLY ACROSS NRN LAKE SUPERIOR AND POSSIBLY INTO THE NRN
PORTIONS OF UPPER MI ON THE SRN TAIL OF THE STRONGER QVECTOR CONV
AND FAVORABLE ISENTROPIC ASCENT JUST AHEAD OF THE SFC TROUGH. MUCAPE
VALUES (LIFTING FROM NEAR 750 MB) OF 500-1000 J/KG STILL SUPPORT A
CONDITIONAL THREAT OF TSRA. ALTHOUGH EFFECTIVE SHEAR VALUES ARE
MARGINAL (20-30 KT) SOME SMALL HAIL MAY BE POSSIBLE WITH ANY TSRA
THAT DEVELOP. CONFIDENCE IN SHRA/TSRA DEVELOPMENT IS LIMITED AS
MODELS HAVE TRENDED TOO HIGH WITH LOW LEVEL MOISTURE AVAILABILITY.
SO...ONLY LOWER END CHANCE POPS WERE INCLUDED.

WED...MODEL SOUNDINGS SHOW STRONG MID-LVL DRYING/SUBSIDENCE IN THE WAKE OF
THE COLD FRONT AS 850 MB TEMPS DROP TO AROUND 5C EARLY WED BUT
REBOUND TO TO AROUND 8C-9C WED AFTERNOON. MIXING HEIGHTS ABOVE 800
MB SHOULD MIX A SIGNIFICANT ENOUGH PORTION OF THE VERY DRY 800-650 MB
LAYER TO DROP DEWPOINTS INLAND TO AROUND 30F. WITH TEMPS INTO THE
LOWER TO MID 70S...RH VALUES WILL DROP TO AROUND 20 PERCENT. NW WIND
SHOULD ALSO INCREASE TO AROUND 15 MPH WITH GUSTS OF 20-25 MPH IN THE
AFTERNOON. SO...A FIRE WEATHER WATCH WAS ISSUED FOR MOST OF INLAND
WEST AND CENTRAL UPPER MICHIGAN.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 625 AM EDT TUE MAY 14 2013

MODEL SNDGS SHOW GOOD MID-LVL DRYING/SUBSIDENCE IN THE WAKE OF THE
COLD FRONT AS 8H TEMPS DROP TO 8-9C. MODELS INDICATE PW VALUES DROP
BLO .5 INCH OR OR 60-70 PERCENT OF NORMAL. GFE MIXED DEWPOINT TOOL
FOR THE NAM AND GFS SHOWS POTENTIAL FOR DEWPOINTS TO DROP INTO THE
LOWER TO MID 20S OVER THE WRN INTERIOR. LOOKING AT HOW DRY MODEL
SNDGS ARE ABV 825 MB THESE DEWPOINTS WOULD NOT BE FAR-FETCHED AT
ALL...ESPECIALLY IF WE MIX NEAR 800 MB. WITH T/TD OF 74/24 MIN RH
VALUES WOULD DROP NEAR 15 PERCENT. NW WIND SHOULD STAY JUST BLO RED
FLAG CRITERIA WITH SUSTAINED WINDS AROUND 15 KT AND GUSTS AROUND 20
KT. HOWEVER IF PCPN IS LIMITED TUE NIGHT...FIRE DANGER WILL
DEFINITELY BE A CONCERN FOR WEDNESDAY. DAY SHIFT MAY NEED TO
COORDINATE WITH FIRE WX USERS TODAY TO SEE IF FIRE WEATHER WATCH MAY
BE NEEDED FOR WED AFTERNOON.

MODELS SHOW A TROUGH MOVING THROUGH THE AREA WED NIGHT BUT NO PCPN
IS EXPECTED FM THIS FEATURE AS THE AIRMASS AND FCST WILL REMAIN DRY
INTO FRI MORNING UNDER CONFLUENT FLOW ALOFT AND BUILDING 5H RDG
HEIGHTS.  EXPECT THE SURFACE RIDGE OF HIGH PRESSURE TO BE DIRECTLY
OVERHEAD ON THURSDAY WHICH WILL RESULT IN LIGHT WINDS AND LAKE
BREEZES CIRCULATIONS.

INCREASING WAA/ISENTROPIC LIFT FRI AFTERNOON INTO SAT MORNING
SPREADING FM WEST TO EAST ACROSS THE CWA WILL BRING AN INCREASED CHC
OF SHOWERS FRI NIGHT INTO SATURDAY MORNING FOR MUCH OF THE CWA. FCST
SHOWALTER INDICES AND MUCAPE VALUES INDICATE CHC OF THUNDERSTORMS
DURING THIS TIME WILL BE MAINLY CONFINED TO THE WEST HALF OF THE CWA
LATE FRI NIGHT INTO SAT MORNING. AS 850 MB WARM FRONT LIFTS NORTH OF
THE CWA BY SATURDAY AFTERNOON...MODEL SNDGS SUGGEST ENVIRONMENT WILL
BECOME CAPPED BY WARMER/DRIER AIR AND THUS EXPECT A LULL IN SHOWER
ACTIVITY FOR SAT AFTERNOON INTO AT LEAST SAT EVENING.

BOTH THE 00Z ECMWF AND GFS INDICATE A SHORTWAVE LIFTING OUT FM BASE
OF UPR TROUGH OVER THE SRN PLAINS AND TOWARD THE UPPER MS VALLEY ON
SUNDAY. THIS SHORTWAVE WILL HELP PUSH FRONTAL BOUNDARY CLOSER TO THE
UPPER MS VALLEY AND OUR WRN CWA ESPECIALLY SUN AFTERNOON. 8H THETA-E
MAXIMUM ALONG THE FRONTAL BOUNDARY AND CORRESPONDING INCREASE IN
INSTABILITY (MLCAPES REACH 700-1200 J/KG OVER WEST HALF) WILL
WARRANT AN INCREASED CHC OF SHRA AND TSRA FOR SUNDAY ESPECIALLY OVER
THE WEST HALF. WILL MAINTAIN HIGH CHC POPS FOR SHRA/TSRA SUN NIGHT
INTO MONDAY ACROSS THE CWA AS MAIN SHORTWAVE AND ASSOC COLD FRONT
MOVE ACROSS THE UPPER GREAT LAKES.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 139 PM EDT TUE MAY 14 2013

VFR CONDITIONS SHOULD PREVAIL AT ALL THREE TAF SITES THROUGH THE
FORECAST PERIOD. A PERIOD OF MID CLOUDS IS EXPECTED THROUGH MID
AFTERNOON AS A BAND OF DISSIPATING LIGHT SHOWERS OR SPRINKLES MOVES
THROUGH WRN UPPER MI. ANOTHER ROUND OF ISOLD SHRA/TSRA POSSIBLE THIS
EVENING AS PRIMARY SFC FRONT ARRIVES. PLENTY OF DRY AIR REMAINS OVER
THE AREA WHICH MAY INHIBIT DEVELOPMENT. WENT FOR SHORT PERIOD OF
VCSH AT CMX WHICH IS IN BEST PROXIMITY TO A DISTURANCE TO THE NORTH
AND LIFT AHEAD OF A WARM FRONT...THEN SHARP DRYING/CLEARING
OVERNIGHT TONIGHT. WILL ALSO SEE GUSTY WEST WINDS IN WAKE OF THE
FRONT...STRONGEST AT THE MORE EXPOSED KCMX.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 422 PM EDT TUE MAY 14 2013

SOUTHERLY FLOW WAS INCREASING AHEAD OF A LOW PRESSURE SYSTEM MOVING
EAST THROUGH SOUTHERN CANADA. WINDS INCREASE TO 25 KTS TONIGHT INTO WED
BUT WILL BE LIMITED AS LOW LEVEL WARM AIR ADVECTION RESULTS IN
INCREASING STABILITY. WINDS ARE EXPECTED TO REMAIN BELOW
30KTS LATER THIS WEEK AND INTO THE WEEKEND. AFTER COOL AND WINTRY
WEATHER FOR THE SPRING SO FAR...SUMMERTIME WEATHER IS BECOMING MORE
COMMON. THUNDERSTORMS ARE POSSIBLE TONIGHT AND ENDING BY
EARLY WEDNESDAY. ANOTHER ROUND OF THUNDERSTORMS WILL BE POSSIBLE
WEST ON SATURDAY/SATURDAY NIGHT...AND ACROSS ALL OF LAKE SUPERIOR
SUNDAY THROUGH MONDAY MORNING.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
     EVENING FOR MIZ002-004>006-009>014-084-085.

LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...JLB
MARINE...JLB