000
FXUS63 KAPX 182322
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
722 PM EDT TUE JUN 18 2013

.SYNOPSIS...
ISSUED AT 332 PM EDT TUE JUN 18 2013

HIGH PRESSURE WILL REMAIN OVER THE GREAT LAKES THROUGH MIDWEEK
BRINGING DRY CONDITIONS AND COOL TEMPERATURES.  SOUTHERLY WINDS
WILL USHER IN A MUCH WARMER AND MORE HUMID AIRMASS HEADING THROUGH
THE END OF THE WEEK INTO THIS WEEKEND. A FRONTAL BOUNDARY
COMBINED WITH SEVERAL UPPER LEVEL DISTURBANCES WILL BRING PERIODIC
CHANCES OF SHOWERS AND THUNDERSTORMS.

&&

.UPDATE...
ISSUED AT 721 PM EDT TUE JUN 18 2013

JUST SOME FINE-TUNING OF THE CLOUD FORECAST SO FAR THIS EVENING.
TEMPS IN THE 60S AND DEW POINTS IN THE 30S CERTAINLY SETS THE
STAGE FOR AN UNSEASONABLY COOL NIGHT...NO CHANGES TO TEMPS AT THIS
POINT.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 332 PM EDT TUE JUN 18 2013

HIGH PRESSURE OVER LAKE SUPERIOR LATE THIS AFTERNOON WILL SETTLE
SOUTHWARD ACROSS THE FORECAST AREA TONIGHT AND WEDNESDAY. THIS WILL
SET THE STAGE FOR MAINLY CLEAR SKIES AND LIGHT WINDS. FROST
POTENTIAL TONIGHT IS THE ONLY REAL FORECAST CONCERN.

TONIGHT...INLAND CU ACROSS PARTS OF NRN LOWER MICHIGAN WILL DIMINISH
OVER THE NEXT SEVERAL HOURS AS DAYTIME HEATING STEADILY WANES...WITH
CLEAR SKIES FOR THE DURATION OF THE NIGHT. SIMILARLY...LAKE BREEZES
(AND WINDS IN GENERAL) WILL DIMINISH EARLY THIS EVENING.

FORECAST WILL INCLUDE PATCHY FROST LATER TONIGHT /HAVE TENTATIVELY
DECIDED TO NOT ISSUE AN ADVISORY/. WINDS...SKY COVER...AND PROXIMITY
OF SURFACE HIGH PRESSURE WILL BE SUPPORTIVE OF FROST. HOWEVER...FULL
GREEN UP CONDITIONS...WEEKEND RAINFALL...AND AFTERNOON SURFACE DEW
POINT TRENDS ARE NOT OVERLY CONDUCIVE FOR WIDESPREAD FROST. COULD
SEE 31-32F IN A FEW OF THE NORMALLY COLDER...OPEN AND/OR LOW LYING
AREAS...BUT OVERALL EXPECT LOWS OF 33-38 AWAY FROM THE GREAT LAKES.
HAVE ESSENTIALLY BLENDED NAM/GFS GUIDANCE...AND FEEL THE GFS MAV IS
TOO COLD.

WEDNESDAY...HIGH PRESSURE WILL SUPPORT MOSTLY SUNNY SKIES...WITH
ONLY SCATTERED INLAND CU EXPECTED. SYNOPTIC FLOW AND SUNSHINE WILL
ALLOW LAKE BREEZES WILL DEVELOP ONCE AGAIN BY AFTERNOON. WITH 850 MB
TEMPS WARMING BY A COUPLE DEGC /COMPARED TO TODAY/ LOOK FOR HIGHS TO
CRACK 70 IN MOST LOCALES - WITH 70-73 EXPECTED AWAY FROM THE BIG
LAKES.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 332 PM EDT TUE JUN 18 2013

MEDIUM RANGE STARTS QUIETLY BUT GETS INCREASINGLY MORE COMPLICATED
WITH MUCH LOWER CONFIDENCE FOR THE END OF THE WEEK INTO THE
WEEKEND.  ON A BROAD SCALE...500MB LONG WAVE TROF GETS EJECTED
EASTWARD AND FLATTENS OUT OVER TIMES AS IT ENCOUNTERS DOWNSTREAM
RIDGING OVER THE EASTERN STATES.  WARM FRONT WILL BECOME DRAPED
ACROSS THE GREAT LAKES...WITH A LARGE DEGREE OF UNCERTAINTY WITH
REGARD TO PRECIPITATION CHANCES.

THURSDAY...AFTER A COOL START TO THE DAY...HIGH PRESSURE WILL
GRADUALLY SLIDE EAST OF THE AREA WITH  MOISTURE BEGINNING TO
INCREASE WITH RETURN FLOW AND APPROACH OF WEAK COOL FRONT. ALTHOUGH
AMBIENT AIR MASS IS QUITE DRY...SLOWLY INCREASING LOW LEVEL MOISTURE
AND WEAK SURFACE BOUNDARY MAY BE ENOUGH TO SPARK A FEW LIGHT SHOWERS
OVER EASTERN UPPER.  OTHERWISE...DRY CONDITIONS WITH INCREASING HIGH
AND MID CLOUDS.  PLEASANT TEMPERATURES IN THE 70S.

FRIDAY INTO THE WEEKEND...LOTS OF UNCERTAINTY AND DIMINISHING
CONFIDENCE IN THE DETAILS.  UPSTREAM RIDGING WILL PUSH EAST AS
WESTERN TROF FLATTENS OUT AS IT EJECTS INTO THE UPPER MIDWEST.  MANY
MODEL DIFFERENCES IN TIMING OF SAID FEATURES...WITH THE 12Z GFS
12-24 HOURS SLOWER THAN THE NAM/ECWMF.  TRENDING TOWARD THE SLIGHTLY
MORE PROGRESSIVE ECMWF SOLUTION...BRINGS A SURFACE WARM FRONT
NORTHWARD INTO THE GREAT LAKES.  BUT HOW FAR NORTH?  AS WE HAVE SEEN
MANY TIMES BEFORE...COLD LAKES FREQUENTLY INHIBIT WARM FRONTS FROM
MAKING IT AS FAR NORTH AS THE MODELS SUGGEST.  FAR TOO MUCH
UNCERTAINTY RIGHT NOW TO SAY MUCH MORE THAN THE WARM FRONT WILL BE
STALLED OUT SOMEWHERE IN THE VICINITY OF NORTHERN MICHIGAN.
NAM/ECMWF HAVE TRENDED A BIT STRONGER WITH UPSTREAM SHORTWAVE ENERGY
ON FRIDAY /GS SLOWER AND WEAKER/...WHICH BRINGS BETTER CHANCES OF
SHOWERS/STORMS FROM THE TIP OF MITT INTO EASTERN UPPER.  COOL
OUTFLOW FROM ANY OF THIS PCPN MAY ALSO PLAY A ROLE IN KEEPING WARM
FRONT A BIT FURTHER SOUTH.  HIGH TEMPS GREATLY DEPENDENT ON CLOUD
COVER/PCPN.  BECAUSE OF THIS...I WILL SPLIT THE DIFFERENCE BETWEEN
GUIDANCE TEMP EXTREMES AND GO WITH HIGHS IN THE 70S...WITH UPPER 60S
TO AROUND 70 IN EASTERN UPPER.

FORECAST REMAINS FUZZY AT BEST INTO THE WEEKEND.  FRONTAL BOUNDARY
IN THE VICINITY OF NORTHERN MICHIGAN ON SATURDAY WITH SOME HINTS IN
THE MODELS OF DRIER AIR TRYING TO NOSE INTO AT LEAST EASTERN
UPPER/NORTHEAST LOWER AS CANADIAN HIGH SLIPS OFF TO THE SOUTHEAST.
DESPITE THIS...WILL NOT BE TOO QUICK TO DEVIATE VERY FAR FROM THE
CURRENT CHANCE OF SHOWERS/STORMS AREA WIDE.  AS PREVIOUS SHIFT
MENTIONED...WOULD NOT BE SURPRISED IF MAIN STORM COMPLEXES REMAIN
SOUTH OF OUR AREA AND MODEL SUGGESTIONS OF DEEPER MOISTURE THIS FAR
NORTH DO NOT MATERIALIZE.  FRONT REMAINS IN THE VICINITY OF NORTHERN
MICHIGAN INTO MONDAY...ALTHOUGH POSSIBLY SHIFTED A BIT FURTHER NORTH
WITH 850MB THERMAL RIDGE BUILDING INTO THE WESTERN LAKES.  ONCE
AGAIN...CHANCE OF SHOWERS/STORMS AREA WIDE WITH TEMPS RUNNING ABOVE
NORMAL.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 112 PM EDT TUE JUN 18 2013

VFR WEATHER. SCATTERED CU WILL DISSIPATE EARLY THIS EVENING...WITH
MAINLY CLEAR SKIES AND LIGHT WINDS THEREAFTER. WITH HIGH PRESSURE
OVERHEAD TONIGHT...LIGHT AND VARIABLE WINDS OVERNIGHT INTO EARLY
WED WILL GIVE WAY TO ONSHORE/LAKE BREEZES BY EARLY WED AFTERNOON.


&&

.MARINE...
ISSUED AT 332 PM EDT TUE JUN 18 2013

MARINERS CAN EXPECT LIGHT WINDS AND LOW WAVES THROUGH
WEDNESDAY /WELL BELOW SMALL CRAFT ADVISORY CRITERIA/ AS HIGH
PRESSURE OVER THE UPPER GREAT LAKES DOMINATES THE REGIONS WEATHER.
ONSHORE LAKE BREEZES CAN BE EXPECTED BY EARLY WEDNESDAY AFTERNOON
NEAR THE COASTS.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.

&&

$$

UPDATE...JZ
SYNOPSIS...NS
SHORT TERM...BS
LONG TERM...JK
AVIATION...BS
MARINE...BS