Area Forecast Discussion Issued by NWS Marquette, MI
000
FXUS63 KMQT 151516 AAA
AFDMQT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
1116 AM EDT SAT JUN 15 2013
.UPDATE...
ISSUED AT 1115 AM EDT SAT JUN 15 2013
OVERALL...ONLY MINOR TWEAKS TO THE GOING FORECAST. MAIN ADJUSTMENTS
WERE TO ADJUST CLOUD COVER UP OVER THE EAST WITH THE MID CLOUDS
REALLY COVERING THAT AREA. ALSO ADJUSTED HIGHS DOWN A COUPLE DEGREES
BASED OFF THE INCREASE CLOUD COVER LIMITING DIURNAL INFLUENCES.
TWEAKED THE POPS SOME TO CAPTURE THE SHOWERS ALONG THE EASTERN EDGE
OF THE SHORTWAVE ROTATING AROUND THE UPPER RIDGE LATE THIS MORNING.
THESE SCATTERED/ISOLATED SHOWERS SHOULD CONTINUE EAST-SOUTHEAST
THROUGH THE AFTERNOON. BEHIND THE SHORTWAVE...TROUGH IS CURRENTLY
MOVING EAST THROUGH EASTERN MN AND THE QUESTION IS IF SHOWERS WILL
DEVELOP ALONG IT IN WESTERN UPPER MICHIAN AS TONGUE OF INCREASED ML
CAPE VALUES AROUND 750 J/KG TRY TO MOVE NORTHEAST ACROSS THE
WISCONSIN BORDER. BEST OPPORTUNITY LOOKS TO BE OVER THE INTERIOR
WEST AND THEN SHIFTING EAST THROUGH THE AFTERNOON. THINK THE
COVERAGE AND INTENSITY WILL BE LIMITED DUE TO THE INCREASING DRY AIR
FROM THE EML SEEN ON THE 12Z KINL/KMPX SOUNDINGS...BUT WILL CONTINUE
SCATTERED/ISOLATED WORDING. FINALLY...DID ADD SOME FOG OVER THE
GREAT LAKES AND ALSO EASTERN UPPER MICHIGAN FOR TONIGHT BASED OFF
THE LATEST MODEL VISIBILITIES AND INCREASING LOW LEVEL MOISTURE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 521 AM EDT SAT JUN 15 2013
TAKING A LOOK AT THE WX MAP THIS MORNING...THE SFC HIGH CENTERED
ACROSS THE OHIO VALLEY AND CENTRAL APPALACHIANS WILL CONTINUE TO
EXTEND A RIDGE ACROSS THE E HALF TO THIRD OF THE CWA THROUGH THIS
MORNING. THIS IS OUT AHEAD OF LOW PRESSURE SITUATED OVER CENTRAL
SASKATCHEWAN. FROM THE WELL WRAPPED-UP LOW EXTENDS A TROUGH THAT WILL
CONTINUE TO SLOWLY PUSH INTO WESTERN AND CENTRAL LAKE SUPERIOR.
SHOWERS AND THUNDERSTORMS /SOME PRODUCING RAINFALL AMOUNTS OF OVER
AN INCH AN HOUR/ HAVE BEEN COMMON OVER NORTHEASTERN MN AND WESTERN
LAKE SUPERIOR. WILL CONTINUE TO MONITOR THE PROGRESSION OF THESE
SHOWERS AND THUNDERSTORMS THROUGHOUT THE DAY...AS UPPER MI REMAINS
IN AN SPC GENERAL RISK. WHILE THE RADAR HAS SHOWN ECHOES OVER THE
EAST HALF...THE PRECIP IS FALLING FROM HIGH CLOUDS...AND LIKELY NOT
REACHING THE GROUND. THE FREEZING LEVEL IS NEAR 9.7KFT...WITH ML
CAPE VALUES RISING ABOVE 500J/KG BY EARLY AFTERNOON. DESPITE
CONTINUED S FLOW...AND INCREASED MOISTURE OVER WESTERN AND MUCH OF
CENTRAL UPPER MI...THE BEST DYNAMICS LOOK TO REMAIN TO OUR SOUTH
TOWARD THIS AFTERNOON /ACROSS WI/...WITH THE SHORTWAVE ROTATING
AROUND THE 500MB RIDGE.
ALTHOUGH THE SFC LOW WILL ELONGATE AND WEAKEN AS IT STRETCHES ACROSS
S MANITOBA THROUGH S ONTARIO AND EASTERN LAKE SUPERIOR
OVERNIGHT...DRIER AIR WILL BE WORKING ITS WAY TOWARDS THE
REGION...WITH JUST A SLIGHT CHANCE OF PRECIP FAR E AROUND OR AFTER
06Z SUNDAY.
OTHER THAN A FEW TWEAKS TO THE QUICKER SHOWER AND TS ACTIVITY THAT
IS BEING POORLY PICKED UP BY THE MODELS...FEW CHANGES WERE NEEDED
THIS FCST PERIOD.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 521 AM EDT SAT JUN 15 2013
MOST OF THE LONG TERM AFTER THIS WEEKEND WILL BE DOMINATED BY NW
FLOW INTO THE UPPER GREAT LAKES BTWN A RIDGE DRIFTING FROM THE
ROCKIES TO THE PLAINS AND A BROAD TROF OVER ERN NAMERICA. COOLEST
WEATHER WILL OCCUR EARLY NEXT WEEK BEHIND SHORTWAVE PASSING THROUGH
SUN NIGHT/EARLY MON. THEN...DESPITE NW FLOW...TEMPS BEYOND
MON SHOULD GENERALLY BE CLOSE TO NORMAL OR EVEN A LITTLE ABOVE
NORMAL SINCE COLDER TEMPS ASSOC WITH THE ERN TROF WILL REMAIN EAST
OF THE UPPER GREAT LAKES. WHILE THERE WILL BE SOME OPPORTUNITIES FOR
PCPN...NW FLOW WILL NOT SUPPORT WIDESPREAD/SIGNIFICANT RAINFALL.
ON SUN...SUBTLE SHORTWAVE RIDGING OVER UPPER MI AHEAD OF SLOWLY
APPROACHING SHORTWAVE (REMNANT OF MID LEVEL LOW) FM NW MN SHOULD
RESULT IN MAINLY DRY WX OVER THE FCST AREA SUN. HOWEVER...NAM
SOUNDINGS SHOW MLCAPE VALUES INCREASING TO 500-700 J/KG TO PERHAPS
UPWARDS OF 1000J/KG IN THE AFTN. FOR THIS REASON...WILL MAINTAIN
SCHC POPS IN THE INTERIOR DURING THE AFTN FOR POTENTIAL OF SOME
DIURNALLY DRIVEN SHRA/TSRA. WITH DEEP LAYER SHEAR FM 30-40KT
...MIGHT EVEN SEE ISOLD SVR STORMS IF THE HIGHER SIDE OF INSTABILITY
RANGE MATERIALIZES. TEMPS SHOULD RISE WELL INTO THE 70S/LWR 80S WITH
A DECENT AMOUNT OF SUNSHINE.
STILL PLENTY OF MODEL DIFFERENCES REGARDING SHORTWAVE AND ASSOC COLD
FRONT MOVING THROUGH THE UPPER GREAT LAKES SUN NIGHT INTO MON. MANY
MODELS PARTICULARLY THE ECMWF AND THE CANADIAN NOW SHOW ONLY WEAK
FORCING ASSOC WITH THE SHORTWAVE AS NOTED ON Q-VECT CONV FIELDS.
GIVEN MODEL UNCERTAINTY AND TREND TOWARD WEAKER FORCING WITH PASSING
SHORTWAVE WILL CONTINUE ONLY CHC POPS FOR SHRA/TSRA SUN NIGHT INTO
MON MORNING. WITH SHORTWAVE SWINGING SE OF UPPER MI MON...EXPECT
SHRA TO END FROM NW TO SE DURING THE DAY WITH GRADUAL CLEARING
FOLLOWING FROM THE W. IT WILL BE A MUCH COOLER DAY...ESPECIALLY NEAR
LAKE SUPERIOR...DUE TO BREEZY N WINDS AND CLOUDS DOMINATING FOR A
GOOD PART OF THE DAY. COOL NIGHT IS EXPECTED FOR MON NIGHT AS HIGH
PRES BUILDS INTO THE UPPER LAKES. WITH DRY AIR MASS (PRECIPITABLE
WATER FALLING TO AROUND 40PCT OF NORMAL) AND WINDS DIMINISHING TO
LIGHT/CALM...CONTINUED TO FAVOR LOWER END OF MODELS GUIDANCE FOR MIN
TEMPS MON NIGHT...ESPECIALLY OVER THE W WHERE SFC HIGH PRES CENTER
WILL BE ARRIVING DURING THE NIGHT. WITH IDEAL RADIATIONAL COOLING
CONDITIONS...MAY SEE SOME OF THE TRADITIONAL COLD SPOTS FALL INTO
THE UPPER 30S.
UPPER MI WILL CONTINUE UNDER NW FLOW ALOFT THROUGH THE END OF THE
WORK WEEK. FOLLOWING NCEP FAVORED ECMWF ENSEMBLE MEAN DECIDED TO
LEAN TOWARD DRIER FCST FOR TUE INTO WED TIME FRAME AS SFC HIGH PRES
RDG HOLDS FIRM. MODEL CONSENSUS SHOWS SERIES OF SHORTWAVES MOVING
THROUGH THE AREA WED NIGHT INTO FRI. SINCE MODELS CONTINUE TO SHOW
INCONSISTENCIES IN TIMING/STRENGTH AND TRACK OF WAVES...CONFIDENCE
WILL BE LIMITED ON PINNING DOWN ANY MINOR PCPN CHANCES. AS A RESULT
ONLY SLIGHT CHC POPS FOR SHRA/TSRA MENTIONED IN FCST FOR LATER IN
THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 757 AM EDT SAT JUN 15 2013
VFR CEILINGS AND VIS WILL DOMINATE THE WEATHER PICTURE OVER THE NEXT
24 HOURS...OUTSIDE OF ANY DEVELOPING STRONGER SHOWERS. THE ONLY
EXCEPTION WILL LIKELY BE AT IWD...WITH SEVERAL UPSTREAM SITES AT
MVFR...IWD MAY FALL TO MVFR CEILINGS AFTER 14Z AND CONTINUE THROUGH
MID AFTERNOON. WINDS AROUND 10KTS OR LESS WILL BE COMMON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EDT SAT JUN 15 2013
OUTSIDE OF STRONGER SHOWERS OR THUNDERSTORMS...GUSTS SHOULD REMAIN AT
OR BELOW 20KTS THROUGH THE PERIOD. THE HIGH OVER THE EASTERN U.S.
WILL KEEP A WEAKENING RIDGE ACROSS EASTERN LAKE SUPERIOR THIS
MORNING. A LOW OVER CENTRAL SASKATCHEWAN WILL EXTEND A TROUGH LAKE
SUPERIOR FROM THIS EVENING THROUGH SUNDAY. THE TROUGH SHOULD EXIT
TOWARD SE CANADA SUNDAY NIGHT INTO MONDAY...AS A STRONGER HIGH SINKS
INTO THE GREAT LAKES FROM THE NORTH...AND LINGERS ACROSS THE REGION
THROUGH WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...SRF
SHORT TERM...KF
LONG TERM...VOSS
AVIATION...KF
MARINE...KF