Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 111753
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
153 PM EDT FRI JUL 11 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EDT FRI JUL 11 2014

UPPER TROUGH IS HEADING EAST ALLOWING WESTERLY FLOW ALOFT AND WARM
AIR ADVECTION IN THE LOW-MID LEVELS ACROSS THE NORTHERN PLAINS. AT
THE SFC...LOW PRESSURE IS OVER NORTHERN SASKATCHEWAN AND MANITOBA
WITH COLD FRONT CROSSING SOUTHERN MANITOBA AND NORTH DAKOTA. LEAD
SHORTWAVE IN THE WEST FLOW IS COMBINING WITH INCREASING H85-H7
MOISTURE TRANSPORT WELL TO EAST OF POOL OF ELEVATED MUCAPES UP TO
1000J/KG OVER THE DAKOTAS TO SPUR ON AREA OF SHRA/TSRA FM CNTRL MN
INTO NORTHWEST WISCONSIN. SHORTWAVE PRESSING EAST AND WINDS ALOFT
MAINLY WEST TO EAST SHOULD ALLOW PORTION OF THIS SHRA/TSRA AREA TO
SURVIVE INTO WESTERN UPR MICHIGAN THIS MORNING. SINCE SHORTWAVE IS
LIFTING ENE ACROSS LK SUPERIOR LATE MORNING INTO THE AFTN...GREATEST
COVERAGE OF SHRA AND POSSIBLE TSRA MAY START TO FOLLOW SIMILAR PATH
SO THE EASTERN HALF OF CWA MAY NOT SEE MUCH PRECIP DURING THE DAY.
TRIED TO CONVEY THIS IN LATEST POPS/WX GRIDS.

TEMPS ARE TOUGH TO GAGE AS DEGREE OF WARMING DEPENDS ON HOW MUCH
CLOUD COVER IS AROUND THIS AFTN. H9-H85 TEMPS ARE WARMING SO WILL
NOT TAKE MUCH SUN TO HAVE TEMPS REACH WELL INTO THE 70S...IF NOT 80
DEGREES. S TO SW WINDS AT SFC A WARMING WIND AWAY FM LK MICHIGAN...SO
WILL NOT PLAY UP THE COOLING DUE TO THE CLOUD COVER TOO MUCH. FEASIBLE
THAT WITHOUT MUCH FORCING THIS AFTN...THERE MAY BE A LULL IN SHRA/TSRA
FOR MOST OF THE CWA. SINCE THERE REMAINS WARM AND MOIST ADVECTION
OVER THE AREA CANNOT GO DRY...BUT WILL HAVE ONLY SMALL CHANCE POPS.
LOW-LEVEL WINDS MAY GET GUSTY AS 25+ KTS ARE WITHIN MIXED LAYER.
AGAIN DEGREE OF ACTUAL MIXING AND WINDS REACHING THE SFC WILL DEPEND
ON THE CLOUD COVER.

ATTN LATER THIS AFTN AND MAYBE EVEN AS LATE AS EARLY THIS EVENING IS
ON STRONGER SHORTWAVE TROUGH SWINGING ACROSS SOUTHERN MANITOBA INTO
NORTHWEST ONTARIO AND ADDITIONAL WAVE CURRENTLY CAUSING SCATTERED
SHRA/TSRA OVER FAR NORTHEAST MONTANA. ASCENT FM THESE WAVES ALONG
WITH THAT CAUSED BY INCREASING DIFFLUENCE VIA 250MB JET STREAK
/WHICH IS ALSO AIDING THE SHRA/TSRA IN MONTANA/ FORECAST TO REACH
NORTHERN MINNESOTA BY THIS AFTN. MLCAPES SHOULD RESPOND IN WAKE OF
THIS MORNINGS SHRA/TSRA IN MN...RESULTING IN MLCAPES AND 1-6KM
MUCAPES OVER 1000J/KG. DEEP LAYER SHEAR OVER 40 KTS OVER THAT AREA
AND SPC DAY1 HAS INDICATED A SLIGHT RISK OF SEVERE STORMS. IF THESE
STORMS DEVELOP THE NEXT QUESTION WILL BE THEIR PROGRESS EAST AND
SOUTHEAST INTO THE EVENING. H7 WINDS WHICH IS PROXY FOR MEAN STORM
MOTION IS W/WNW TO E/ESE 30-35 KTS SO STORMS WILL TRY TO SLIDE INTO
WESTERN CWA. GEM-REGIONAL MOST AGGRESSIVE WITH THAT IDEA...BUT OTHER
HIGH RES MODELS SUGGEST AT LEAST REMNANTS OF STRONGER STORMS COULD
MAKE IT TO THE EAST. H85 WINDS UP TO 30 KTS AHEAD OF THE STORMS AND
THE HIGHER MUCAPE VALUES MAY ACT TO SUSTAIN THESE STORMS EVEN AS THEY
CROSS ONTO STILL CHILLY WATERS OF LK SUPERIOR AS IT WOULD ALLOW THEM
TO BECOME ELEVATED INSTEAD OF SURFACE BASED. IT IS REALLY HARD TO
TELL THAT AT THIS POINT THOUGH AND THIS BECOMES MORE OF A NEAR-
TERM/NOWCAST ISSUE. 0-3KM SHEAR 25-40 KTS SUGGESTS IF THE STORMS DO
BECOME ELEVATED AND RIDE ATOP THE MARINE LAYER THEY COULD BECOME
ORGANIZED AND FORWARD PROPAGATE TO THE EAST/SOUTHEAST ALONG 850-300MB
THICKNESSES AND WITH THE FORWARD PROPAGATING CORFIDI VECTORS.

SEEMS TO BE ENOUGH RISK OF THIS TO INCLUDE A MENTION FOR STRONGER
STORMS OVER WESTERN LK SUPERIOR AND ISLE ROYALE. NO MENTION OF
STRONGER STORMS FARTHER EAST THOUGH AS THAT CERTAINTY DECREASES
SHARPLY TOWARD THE WESTERN LAND CWA OF UPR MICHIGAN. DO EXPECT
SCATTERED SHRA/TSRA AS THE LARGER SCALE FORCING LINKS UP WITH THE
COLD FRONT AS IT MOVES TOWARD UPR MICHIGAN...JUST NOT SURE ON THE
STRENGTH OF THE STORMS. CERTAINLY A LOT OF QUESTIONS WITH SPECIFICS
SO THE POPS WILL STAY IN THE LOWER CHANCE RANGE FOR NOW. SFC FRONT
ONLY MAKES IT TO FAR WEST UPR MICHIGAN LATE TONIGHT...BUT H85 WINDS
VEERING MORE WSW ADVECT GREATER MOISTURE AND INSTABILITY OUT OF THE
EASTERN CWA AFTER MIDNIGHT. WOULD EXPECT DIMINISHING TREND TO
SHRA/TSRA AFTER MIDNIGHT AS THIS OCCURS. DROPPED POPS AFTER MIDNIGHT
IN THE WEST...AND WENT WITH PARTIAL CLEARING OF CLOUDS. AHEAD OF THE
FRONT TONIGHT...TEMPS MOST AREAS WILL REMAIN IN THE 60S.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 418 AM EDT FRI JUL 11 2014

UNCERTAINTY STILL EXISTS FOR THE WEEKEND AS SUBTLE SHORTWAVES AND
CONVECTIVE COMPLEXES MAKE FORECASTING DIFFICULT.

FOR SAT...THE LOW PRESSURE SYSTEM OVER CENTRAL CANADA WILL REMAIN
STATIONARY AS A WEAK COLD FRONT MOVES INTO THE CWA. THE FRONT WILL
BE OVER NWRN UPPER MI AT 12Z SAT AND LOOKS TO WASH OUT AS IT MOVE
FARTHER INTO UPPER MI. THINK THERE COULD BE SCATTERED SHOWERS AND
THUNDERSTORMS ALONG THE FRONT OVER NWRN UPPER MI. AM MORE UNCERTAIN
WITH CONVECTIVE CHANCES OVER CENTRAL/ERN UPPER MI AS MODELS SHOW A
CONVECTIVE COMPLEX MOVING S OF THE CWA SOMETIME LATE SAT AFTERNOON
INTO EARLY SAT NIGHT. THE NAM IS THE FARTHEST N WITH SHOWING THE
COMPLEX SKIRTING THE SERN CWA. WHILE THIS CANNOT BE COMPLETELY RULED
OUT...WENT MORE WITH THE CONSENSUS APPROACH IN KEEPING THE COMPLEX
FARTHER S. DEPENDING ON THE STRENGTH/TRACK/TIMING OF THE COMPLEX /IF
IT FORMS/...CONVECTION MAY OR MAY NOT DEVELOP FARTHER N OVER THE
CENTRAL AND ERN CWA. IF CONVECTION TO THE S IS MORE
MINIMAL...CONVECTION MAY BE ABLE TO STRENGTHEN OVER THE SCENTRAL CWA
WHERE CAPE VALUES MAY EVEN RISE TO NEAR 1000J/KG WITH DEEP LAYER
SHEAR AROUND 40KTS.

A STRONGER COLD FRONT MOVES THROUGH ON SUN...WITH MODEL VARIABILITY
WITH THE TIMING OF THAT FRONT...ALTHOUGH THE MAJORITY OF MODELS HAVE
IT PASSING THROUGH MUCH OF THE AREA IN THE MORNING TO EARLY
AFTERNOON. THIS DOES NOT ALLOW MUCH TIME FOR INSTABILITY TO DEVELOP.
THINK THAT SCATTERED SHOWERS WILL DEVELOP ALONG THE FRONT OVER
MAINLY ERN UPPER MI...WHERE AT LEAST SOME HEATING WILL OCCUR BEFORE
THE FRONT...AND A WEAK SHORTWAVE RIDING ALONG THAT FRONT...PASSES
THROUGH. PRECIP CHANCES PUSH S THROUGH THE DAY ALONG WITH THE FRONT.

BY 12Z MON...THE UPPER LOW THAT WAS OVER CENTRAL CANADA WILL BE NEAR
INL. THE LOW WILL THEN SHIFT SE AND ACROSS THE GENERAL AREA INTO
TUE...AND SHOULD BE E OF THE CWA BY WED AT THE LATEST...WITH THE GFS
MOVING IT OUT FAR FASTER THAN THE ECMWF AND GEM-NH. AS THAT UPPER
LOW MOVES IN ON MON...THE COLD CORE BEING OVERHEAD OR NEARBY
COMBINED WITH THE HEIGHT FALLS AND DYNAMICS OF THE SYSTEM WILL LEAD
TO SCATTERED SHOWERS OVER MUCH OF THE AREA ON MON INTO TUE.

WITH HOW ANOMALOUSLY STRONG THE LOW WILL BE...THE BIG STORY IN THE
LONG TERM IS TEMPERATURES. 850MB TEMPS WILL BE COLDEST ON TUE AT
4-5C...RESULTING IN HIGH TEMPERATURES IN THE LOW 50S /OR POSSIBLE
NOT EVEN REACHING 50/ OVER NRN UPPER MI...WITH HIGHS IN THE LOW 60S
OVER SCENTRAL UPPER MI. RECORD LOW HIGH TEMPS FOR TUE AT NWS
MARQUETTE IS DEGREES...WHICH QUITE LIKELY WILL BE WARMER THAN WHAT
WE SEE ON TUE. IN FACT THE COLDEST HIGH TEMP FOR THE MONTH OF JULY
IS 51...AND THAT IS NOT EVEN OUT OF THE REALM OF POSSIBILITIES TO
TIE OR BREAK. ALTHOUGH TEMPS DO WARM WED AND THU...THEY SHOULD
CONTINUE TO BE BELOW NORMAL.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 152 PM EDT FRI JUL 11 2014

A BAND OF LIGHT SHOWERS MOVING THROUGH UPPER MICHIGAN THROUGH EARLY
AFTERNOON IS NOT EXPECTED TO BE HEAVY ENOUGH...PER RADAR TRENDS...TO
REDUCE CONDITIONS TO MVFR. THE NEXT SHOT OF SOME SHRA AND POSSIBLE
TSRA IS EXPECTED THIS EVENING AS A WEAK COLD FRONT APPROACHES FROM
MN. LOCATION AND COVERAGE OF ANY PCPN IS QUITE UNCERTAIN...SO ONLY A
VCNTY SHRA MENTION WAS INCLUDED FOR NOW. LIKE TODAY...CONDITIONS
SHOULD STAY MAINLY VFR INTO SATURDAY MORNING.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EDT FRI JUL 11 2014

HIGH PRESSURE OVER THE LOWER GREAT LAKES SHIFTS EASTWARD THIS MORNING
AS A TROUGH DEVELOPS OVER THE UPPER MS VALLEY. SOUTH WINDS OF UP TO
20 KTS...POSSIBLY 25 KTS AT HIGHER PLATFORMS ABOVE MARINE LAYER...
EXPECTED INTO THIS EVENING...WITH WINDS SHIFTING TO SW LESS THAN 15
KTS LATE TONIGHT. POTENTIAL FOR STRONGER STORMS OVER WESTERN LK
SUPERIOR THIS AFTN OR EVENING. ADDITIONALLY...FOG WILL BE POSSIBLE
ACROSS THE ENTIRE LAKE WITH THE TROUGH PASSAGE. LIGHT WINDS WILL
CONTINUE THROUGH SUNDAY BEFORE ANOTHER TROUGH PASSES SOUTHEASTWARD
ACROSS LAKE SUPERIOR SUNDAY NIGHT. GUSTY NORTHWEST WINDS TO 20 KNOTS
EXPECTED BEHIND THIS TROUGH EARLY NEXT WEEK AS HIGH PRESSURE BUILDS
OVER THE NORTHERN PLAINS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLA
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLA





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