Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 301913
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
313 PM EDT SAT AUG 30 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 448 AM EDT SAT AUG 30 2014

MANY AREAS OF SHOWERS AND ISOLD TSRA IMPACTING UPR GREAT LAKES THIS
MORNING. WV LOOP POINTS TO PRIMARY SHORTWAVE FM CENTRAL IOWA INTO
WESTERN WI WITH ASSOCIATED SFC LOW OVER WESTERN WISCONSIN...LIFTING
NORTHEAST TOWARD UPR MICHIGAN. SFC TROUGH/COOL FRONT EXTENDS FM THAT
LOW TO THE NORTH OVER WESTERN UPR MICHIGAN. SHRA/TSRA OVER EASTERN
SECTIONS OF CWA MAINLY TIED TO H85 MOISTURE TRANSPORT AND ON EDGE OF
UP TO 1000J/KG OF MUCAPE LIFTED FM 1KM. HAVE BEEN ISOLD TSRA WITHIN
LAST FEW HOURS VCNTY OF ESC/ISQ/ERY...BUT LIMITED DEPTH OF CORES
WITH THE TSRA IS LIKELY JUST RESULTING IN BRIEF HEAVY DOWNPOURS.
SHOWERS/RAIN OVER WI WITH NOT NEAR AS MUCH TSRA ARE DUE TO H85-H5
Q-VECTOR CONVERGENCE AND UVM FM THE SHORTWAVE WITH UVM ALSO AIDED
BY SFC-H85 LOWS.

EXPECT DECENT COVERAGE OF SHOWERS THROUGH MIDDAY MAINLY OVER EAST
HALF OF CWA AS THE SHORTWAVE LIFTS TO THE NORTHEAST. UPSLOPE NORTH
FLOW IN WAKE OF FRONT SETTLING OVER NORTHERN UPR MICHIGAN WILL ALSO
HELP OUT THE SHOWERS AND COULD EVEN RESULT IN SOME DZ AND FOG. TEMPS
WILL GO NOWHERE FAST...WITH MINIMAL CHANGE IN THE MAINLY 60S
READINGS OVER THE WEST AND NORTH DUE TO COOL ADVECTION AS WINDS TURN
OFF LK SUPERIOR. COULD SEE TEMPS REACH AROUND 70 DEGREES IN THE FAR
SOUTH OR SOUTHEAST CWA THIS AFTN...BUT THIS WILL DEPEND ON HOW
QUICKLY THE WIDESPREAD SHOWERS EXIT THIS AFTN. SINCE IT IS ALREADY
IN THE MIDDLE 60S THIS MORNING...WOULD NOT TAKE MUCH TO PUSH PAST 70
DEGREES. TSRA CHANCES FROM HERE ON OUT SEEM MINIMAL AS THE STRONGER
LOW-LEVEL JET AND MOISTURE TRANSPORT WILL STAY EAST AND SOUTHEAST OF
UPR MICHIGAN. KEPT CHANCES HIGHEST OVER FAR SOUTH AND EAST CWA ON
EDGE OF 0.5-1.0KM MUCAPE AND IN SIMILAR REGION TO WHERE TSRA ARE
CURRENTLY ONGOING. LIMITED INSOLATION AND WEAK LOW-LEVEL MOISTURE
ADVECTION SHOULD RESULT IN VERY LIMITED POTENTIAL OF ANY STRONGER
STORMS. HEAVY DOWNPOURS SHOULD BE THE PRIME HAZARD WITH ANY TSRA.

LAST ITEM FOR TODAY. NEAR LK SUPERIOR LATER THIS AFTN AS NORTH WINDS
INCREASE THERE COULD BE MODERATE SWIM RISK DEVELOP FM MQT TO GRAND
MARAIS. SOUNDINGS INDICATE SHALLOW DEPTH TO MIXED LAYER BUT THERE
COULD BE PERIOD OF 15-20 KT WINDS TO THE SFC WITH WAVES INCREASING
TO 4 FT.

FOR TONIGHT...SHOWERS WILL GRADUALLY DIMINISH OVER THE EAST HALF.
SOUNDINGS AND CROSS-SECTIONS FM NAM/GFS/GEM-REGIONAL POINT TO A LOT
OF LOW-LEVEL MOISTURE STAYING IN PLACE THOUGH. SFC LOW NEAR SAULT
STE MARIE THIS EVENING RESULTS IN A NNW CYCLONIC FLOW SFC-H9 MAINLY
FM MQT TO ERY. KEPT SMALL POPS GOING FOR THESE AREAS THROUGH AROUND
MIDNIGHT. COULD EVEN BE MORE OF A DRIZZLE TYPE SETUP AS DEEPER
MOISTURE THINS OUT. WITH THAT THINNING MID-LEVEL MOISTURE...COULD
ALSO SEE AREAS OF FOG LATER AT NIGHT AS BLYR COOLS AND SINCE THERE
IS PLENTY OF LOW-LEVEL MOISTURE LINGERING. HIGHEST PROBABILITY FOR
DENSE FOG WILL BE INLAND OVER THE WEST HALF.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 312 PM EDT SAT AUG 30 2014

SUN NIGHT AND MON...A SHORTWAVE TROUGH AND ASSOCIATED EXIT REGION OF
THE UPPER JET WILL CATCH UP WITH A SFC TROUGH/COLD FRONT INITIALLY
FROM FROM THE SRN MANITOBA/ONTARIO BORDER TO THE CENTRAL PLAINS
STATES. MODELS ARE IN GOOD AGREEMENT IN SHOWING THE SHORTWAVE AND
JET EXIT REGION MOVING ACROSS THE CWA MON...WITH A 997MB LOW FORMING
ALONG THE MN/ONTARIO BORDER AND DEEPENING TO AROUND 988MB WHILE
MOVING TO HUDSON BAY BY 06Z TUE. THIS BRINGS THE COLD FRONT INTO WRN
LAKE SUPERIOR BY 12Z MON...WRN UPPER MI BY 18Z MON...CENTRAL UPPER
MI BY 00Z TUE AND JUST E OF THE CWA BY 06Z TUE. WHILE PRECIP LOOKS
TO BE A CERTAINTY ACROSS THE CWA...EXACT PRECIP AMOUNTS AND SEVERE
POTENTIAL IS A LOT MORE UNCERTAIN DUE TO A COUPLE OF FACTORS. MODEL
QPF FIELDS HINT AT THE FORMATION OF A CONVECTIVE COMPLEX DURING THIS
TIME FRAME...BUT CONFIDENCE OF IF/WHEN/WHERE THAT COULD HAPPEN IS
QUITE LOW. ALSO...WHILE THE KINEMATICS OF THIS SYSTEM ARE QUITE
STRONG /0-6KM SHEAR OF 40-50KTS AND 0-1KM SHEAR OF 20-30KTS/...THE
MAGNITUDE OF INSTABILITY IS NOT AS IMPRESSIVE. WITH THE TIMING OF
THE FRONT...EXPECT BEST CHANCES FOR CAPE BUILDUP WILL BE OVER THE
ERN CWA WHERE CLOUDS/PRECIP WILL NOT MOVE IN AS EARLY. STILL TOO
EARLY/UNCERTAIN TO HAVE GOOD FEEL FOR SEVERE POTENTIAL...BUT IT CAN
NOT BE RULED OUT.

TUE LOOKS DRY FOR THE MOST PART AS UPPER RIDGING MOVES IN BEHIND THE
PREVIOUS SYSTEM. TEMPS SHOULD BE SEASONAL AS 850MB TEMPS WILL BE
9-11C...LEADING TO HIGH TEMPS FROM THE UPPER 60S TO MID 70S.

FORECAST FOR WED THROUGH NEXT SAT IS UNCERTAIN AS ZONAL FLOW LOOKS
TO BE THE OVERALL PATTERN BUT MODELS VARY SIGNIFICANTLY FROM EACH
OTHER AND FROM RUN TO RUN ON A FEW POTENTIAL ROUNDS OF SHORTWAVE
ENERGY MOVING THROUGH OR NEARBY. THE EXTENDED FORECAST DOES FAVOR
PERIOD OF SHOWERS AND POSSIBLY THUNDERSTORMS...BUT TIMING/COVERAGE
IS QUITE UNCERTAIN. DEPENDING ON CLOUD/PRECIP COVERAGE...IT DOES
APPEAR A WARMING TREND IS IN STORE THROUGH AT LEAST THU...WITH TEMPS
RISING TO ABOVE NORMAL LEVELS. WILL USE CONSENSUS OF MODEL GUIDANCE FOR
THE LAST HALF OF THE UPCOMING WEEK.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1256 PM EDT SAT AUG 30 2014

THERE COULD BE SOME IMPROVEMENT THIS AFTN AT KIWD AND KCMX...BUT
KSAW MAY REMAIN IN THE IFR CATEGORY THROUGH THE ENTIRE AFTN. GOOD
CHANCE OF VERY LOW CONDITIONS IN FOG OVERNIGHT AT ALL SITES AS WINDS
BECOME LIGHT. VFR CONDITIONS WILL RETURN SUN MORNING AS DRY AIR
MOVES IN AND MIXING OCCURS AT ALL SITES.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EDT SAT AUG 30 2014

LOW PRESSURE CROSSING THE REGION TODAY WILL RESULT IN A WIND SHIFT
WITH MOST OF LK SUPERIOR SEEING NORTH-NORTHEAST WINDS BY EARLY AFTN.
WINDS WILL BE LESS THAN 20 KTS THOUGH. HIGH PRESSURE LIGHTENS WINDS
TONIGHT THROUGH SUNDAY. A STRONG LOW PRESSURE SYSTEM THEN CROSSES
THE REGION ON MONDAY INTO MONDAY NIGHT. SOUTHERLY WINDS TO AROUND
25KTS EXPECTED OVER EASTERN LAKE SUPERIOR ON MONDAY...WITH WINDS
SHIFTING TO WEST-NORTHWEST 20-25 KTS OVER MUCH OF THE LAKE ON
MONDAY NIGHT. W-SW WINDS ARE EXPECTED TO BE LESS THAN 20KTS
TUESDAY AND WEDNESDAY.
&&

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

$$

SHORT TERM...JLA
LONG TERM...TITUS
AVIATION...07
MARINE...JLA





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