Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 180802
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
402 AM EDT FRI JUL 18 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 340 PM EDT THU JUL 17 2014

RADAR TRENDS AROUND 20Z WAS SHOWING A FEW RETURNS HOWEVER...LITTLE
PRECIPITATION IS LIKELY REACHING THE GROUND. VISIBLE SATELLITE
IMAGERY IS SHOWING A DECENT CU FIELD CONTINUING ACROSS THE U.P. THIS
MAKES SENSE AS CONVECTIVE TEMPS ARE IN THE LOW 70S...WHICH IS WHAT
MANY OF THE OBSERVATIONS ARE SHOWING. WV IMAGERY IS SHOWING A WEAK
SHORTWAVE MAKING ITS WAY INTO NORTHERN MN WHILE THE OVERALL BROAD
TROUGHING CAN BE NOTED OVER THE EASTERN SEABOARD.

LATE THIS AFTERNOON...THE SURFACE HIGH SLIDING TO THE SOUTHEAST OF
THE AREA WILL ALLOW SOUTHWESTERLY FLOW TO PUSH BACK INTO THE AREA.
THIS WILL ALLOW MOISTURE TO SLOWLY INCREASE ACROSS THE U.P. THE MAIN
TROUGH AXIS THAT HAS LINGERED OVER THE PAST FEW DAYS WILL CONTINUE
TO SHIFT FARTHER TO THE EAST OF THE AREA...BUT MODELS ARE HINTING
THAT THE WEAK SHORTWAVE SHOWING UP IN WV IMAGERY WILL PRESS EASTWARD
INTO THE U.P. LATER THIS AFTERNOON. THE COOLER AIR ALOFT ASSOCIATED
WITH THIS THIS FEATURE COULD ALLOW FOR A FEW ISOLATED SHOWERS TO
DEVELOP...THE AREA OF FOCUS WOULD LIKELY BE OVER THE WESTERN HALF OF
THE U.P. ESPECIALLY IF LAKE BREEZE BOUNDARIES CAN ADD ENOUGH LIFT TO
ALLOW THESE TO FORM. HAVE KEPT ONLY A SLIGHT MENTION AND CONTINUED
AN INCREASE IN CLOUD COVER DURING THE LATE AFTERNOON HOURS.

TONIGHT THROUGH FRIDAY...THE HIGH PRESSURE SYSTEM WILL LIFT
NORTHEASTWARD INTO THE LOWER GREAT LAKES ALLOWING MOST OF THE U.P.
TO REMAIN IN WARMER AND MORE MOIST FLOW. WINDS WILL BE FAIRLY LIGHT
TONIGHT...HOWEVER...WIND SPEEDS WILL INCREASE SLIGHTLY BY FRIDAY
AFTERNOON AS INCREASED PRESSURE GRADIENT BETWEEN THE HIGH TO THE
EAST AND A LOW PRESSURE CENTER MAKING ITS WAY ACROSS THE
SASKATCHEWAN/MANITOBA BORDER. OVERALL CLOUD COVER WILL DIMINISH THIS
EVENING INTO THE OVERNIGHT HOURS AS THE SURFACE TEMPS COOL ALLOWING
THE DIURNAL CU TO DISSIPATE. DURING THE DAY FRIDAY...EXPECT A
SIMILAR TREND AS TODAY WITH DIURNAL CU DEVELOPING BY
18Z...HOWEVER...PRECIPITATION CHANCES WILL BE MARGINAL AT BEST
ESPECIALLY WITH THE LACK OF A SHORTWAVE PUSHING THROUGH THE AREA
ALONG WITH EVEN LESS OVERALL MOISTURE SHOWN IN THE SOUNDING.
ADDITIONALLY...ALOFT...500MB HEIGHTS SHOW ZONAL TO SLIGHT RIDGING
ACROSS THE AREA...HELPING TO INCREASE THE OVERALL CAPPING.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 402 AM EDT FRI JUL 18 2014

QUITE A COMPLICATED MID-RANGE FORECAST AT HAND AS A SERIES OF
MID-LEVEL TROUGHS AND ASSOCIATED CONVECTIVE ACTIVITY COMBAT A
BUILDING RIDGE OVER THE UPPER GREAT LAKES THIS WEEKEND INTO EARLY
NEXT WEEK. MOST PRECIP SHOULD REMAIN CLEAR OF UPPER MI...THOUGH
UNCERTAINTY IN CONVECTIVE EVOLUTION TO THE NW WILL KEEP SMALL
CHANCES OF PRECIP IN THE FORECAST BEGINNING SATURDAY AFTERNOON.
TEMPERATURES WILL BE ABOVE AVERAGE THROUGH EARLY NEXT WEEK.

SATURDAY...A POTENT SHORTWAVE TROUGH AND ASSOCIATED 994 HPA SFC LOW
CURRENTLY INDUCING CONVECTION ACROSS CENTRAL AND SOUTHERN ALBERTA
WILL TRACK EASTWARD TO FAR NORTHWEST ONTARIO BY 12Z SATURDAY.
MID-RANGE GUIDANCE IS IN GOOD AGREEMENT ON THIS EVOLUTION. THE SFC
LOW WILL EJECT NORTHEASTWARD THROUGH THE DAY SATURDAY AND LAY OUT A
DECAYING SFC TROUGH FROM NORTHERN MN TO SOUTHERN JAMES BAY.
CONVECTIVE ACTIVITY LOOKS TO BE FAIRLY WIDESPREAD ACROSS MN ON
SATURDAY...WITH MIXED SIGNALS ON HOW FAR EAST IT TRAVELS SATURDAY
NIGHT. ALL MODELS ARE PAINTING SOME QPF ACROSS THE FAR WEST CWA BY
SATURDAY AFTERNOON...WITH MUCH OF THE PRECIP DISSIPATING WITH THE
LOSS OF DAYTIME HEATING SATURDAY NIGHT. IT IS HARD TO ARGUE AGAINST
SOME PRECIP REACHING THE WESTERN CWA SATURDAY NIGHT AS LOW-LEVEL WAA
WILL ONLY BE IN THE BEGINNING STAGES OF BUILDING A MID-LEVEL RIDGE
OVER THE AREA.

SUNDAY...COMPLICATIONS IN THE FORECAST INCREASE BY SUNDAY AS
CONVECTION DECAYS SATURDAY NIGHT. THE COMBINATION OF ANY CONVECTIVE
OUTFLOW AND THE RELATIVE COLD WATERS OF LAKE SUPERIOR COULD BRING
THE STALLED SFC TROUGH A TOUCH FARTHER SOUTH THAN PREVIOUSLY
THOUGHT...PROVIDING A FOCUS FOR INCREASED CONVERGENCE. HOWEVER...BY
THIS TIME 850HPA TEMPS WILL BE INCREASING AND BUILDING A STOUT CAP
ACROSS THE AREA. DECIDED TO KEEP PRECIP OUT OF THE FORECAST UNTIL
SUNDAY EVENING GIVEN SO MANY UNCERTAINTIES. EITHER WAY...WITH
INCREASING LOW-LEVEL TEMPS...HIGHS SHOULD REACH WELL INTO THE 80S
FOR MOST LOCATIONS ACROSS THE WEST.

HIGHER MOISTURE SURGES NORTHWARD AHEAD OF THE NEXT SHORTWAVE TROUGH
AND WILL BE ENOUGH TO INDUCE SOME ELEVATED CONVECTION ON A WEAK LLJ.
HAVE OPTED TO INCREASE POPS SLIGHTLY OVER WESTERN LAKE SUPERIOR AND
THE NORTHWEST HALF OF THE CWA.

MONDAY...THE WEATHER HITS A REWIND BUTTON BY MONDAY AND PRODUCES A
SIMILAR SETUP WITH THE SAME QUESTIONS AS SATURDAY. ANOTHER MID-LEVEL
TROUGH AXIS IS PROGGED TO BE OVER NORTHERN MANITOBA BY 18Z MONDAY.
THE ASSOCIATED SFC LOW WILL PUSH A COLD FRONT SOUTHWARD TOWARD
NORTHERN LAKE SUPERIOR TROUGH THE DAY. WITH THAT SAID...FORECAST
SOUNDINGS ARE INDICATING A DECENT CAP AT AROUND 850HPA AND RESULTANT
CONVECTIVE TEMPS IN THE UPPER 90S. EVEN WITH ENHANCED CONVERGENCE
ALONG THE SFC TROUGH...THIS CAP WOULD BE QUITE DIFFICULT TO
OVERCOME. HAVE LOWERED POPS ACROSS MUCH OF THE AREA...WITH ONLY SOME
SLIGHT CHANCES ACROSS THE NORTH HALF TO ACCOUNT FOR DECAYING PRECIP.

TEMPS ON MONDAY HAVE THE CHANCE TO GET QUITE WARM ACROSS THE WEST
HALF AS 850HPA TEMPS RISE TO OVER 20C. MAX TEMPS APPROACHING 90F
WILL NOT BE OUT OF THE QUESTION FOR SOME PLACES. HOWEVER...CLOUD
COVER AND ANY LINGERING PRECIP COULD KEEP TEMPS DOWN...SO DID NOT GO
WITH THE HIGHER END OF GUIDANCE ATTM.

TUESDAY THROUGH THURSDAY...MODEL SOLUTIONS DIVERGE BY THIS POINT AS
A THIRD SHORTWAVE ROUNDS A BUILDING RIDGE OVER THE NORTHERN PLAINS.
THE GFS IS THE MOST AGGRESSIVE WITH THIS SHORTWAVE...PRODUCING A
1006HPA LOW OVER UPPER MI BY WEDNESDAY AFTERNOON. THE ECMWF PLACES A
THE LOW OVER SOUTHEAST MN...AND THE GEM FARTHER SOUTH OVER NORTHERN
IL. PRECIP CHANCES LOOK THE BEST TUESDAY AND TUESDAY NIGHT WHERE
MODEL GUIDANCE LINES UP QPF THE BEST. BY WEDNESDAY...THE UNCERTAINTY
IN HOW FAR SOUTH THE DEVELOPING LOW WOULD GO WAS ENOUGH TO WARRANT
HIGH-END SLIGHT CHANCE TO LOW-END CHANCE POPS. HIGH PRESSURE THEN
BUILDS ACROSS THE AREA THROUGH THE DAY THURSDAY...BRINGING COOLER
AND DRIER WEATHER.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 110 AM EDT FRI JUL 18 2014

VFR CONDITIONS ARE EXPECTED TO CONTINUE AT KIWD/KCMX/KSAW THROUGH
THE FORECAST PERIOD. WINDS WILL REMAIN LIGHT UNTIL LATER THIS
MORNING WHEN GRADIENT BEGINS TO TIGHTEN AND SOUTHERLY WINDS INCREASE.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 329 PM EDT THU JUL 17 2014

WINDS WILL STAY AT OR BELOW 20 KNOTS THIS FORECAST PERIOD. A RIDGE
OF HIGH PRESSURE WILL CONTROL THE WEATHER THROUGH THE WEEKEND. LOW
PRESSURE WILL BEGIN TO APPROACH THE GREAT LAKES REGION FROM THE
EASTERN CANADIAN PRAIRIES MONDAY THROUGH WEDNESDAY BRINGING
SOUTHERLY WINDS. FOG MAY BECOME AN ISSUE ACROSS THE GREAT LAKES INTO
THE BEGINNING OF NEXT WEEK AS MOISTURE PUSHES INTO THE AREA.
&&

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

$$

SHORT TERM...KEC
LONG TERM...KLUBER
AVIATION...JLB
MARINE...KEC






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