000
FXUS63 KAPX 230549
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
149 AM EDT THU MAY 23 2013

.SYNOPSIS...
ISSUED AT 400 PM EDT WED MAY 22 2013

LOW PRESSURE WILL SLOWLY MOVE ACROSS THE AREA TONIGHT...GENERATING
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS...ESPECIALLY ACROSS
NORTHERN LOWER MICHIGAN. LARGE AND SLOW MOVING HIGH PRESSURE BUILDS
INTO THE AREA LATER THURSDAY...REMAINING OVERHEAD RIGHT THROUGH THE
UPCOMING HOLIDAY WEEKEND. THIS SYSTEM WILL BRING COOL LATE MAY
AIR...ALONG WITH PLENTY OF SUNSHINE.

&&

.UPDATE...
ISSUED AT 141 AM EDT THU MAY 23 2013

FORECAST IN GREAT SHAPE. PERIODS OF RAIN WILL CONTINUE WITH A NW
TO SE TRANSITION OF THE BACK EDGE OF THE PRECIPITATION...AS THE
UPPER TROUGHING PUSHES EAST.

UPDATE ISSUED AT 1017 PM EDT WED MAY 22 2013

AS EXPECTED...PRECIP HAS FILLED IN NICELY ACROSS THE EASTERN U.P.
AS MID LEVEL DEFORMATION AXIS CONTINUES TO ELONGATE ACROSS THE
REGION...WHILE PRECIP SOUTH OF M-55 HAS BECOME MORE SPOTTY WITH
TIME. STILL ANTICIPATE PERIODS OF RAIN/SHOWERS FOR ALL AREAS
OVERNIGHT...INCREASINGLY CONFINED TO NORTHERN LOWER AFTER 09Z AS
THE PARENT UPPER TROUGH SWINGS THROUGH THE U.P. AND PUTS AN END TO
LINGERING FORCING UP THAT WAY...WHILE SOME MUCH DRIER AIR ALSO
BLEEDS IN RATHER QUICKLY BY 12Z. NORTHERN LOWER WILL TAKE A BIT
LONGER TO RID ITSELF OF THE CLOUDS AND RAIN...PERHAPS AS LATE AS
18Z...AND BASED ON LATEST SATELLITE AND SHORT TERM GUIDANCE
TRENDS...HAVE BACKED UP THE ARRIVAL OF SUNSHINE SOUTH OF M-32 BY A
FEW MORE HOURS INTO EARLY THURSDAY AFTERNOON. STILL ANTICIPATE A
GOOD DEAL OF LATE DAY SUN FOR ALL AREAS.

UPDATE ISSUED AT 749 PM EDT WED MAY 22 2013

NO BIG CHANGES NEEDED AT THE MOMENT...BUT HAVE REWORKED THE GOING
PRECIP FORECAST TO ENHANCE COVERAGE INTO THE EASTERN U.P. THE NEXT
FEW HOURS. ELONGATED SURFACE LOW CONTINUES TO TRACK TOWARD THE
THUMB REGION AT THIS HOUR...ALL WHILE A CLOSED MID LEVEL CIRCULATION
IS MEANDERING THROUGH IOWA...INCREASINGLY PINCHED OFF FROM THE
UPPER LEVEL FLOW WITH A SECONDARY UPPER TROUGH SWINGING THROUGH
ONTARIO. MID LEVEL DEFORMATION DYNAMICS IN COMBINATION WITH BOTH
UPPER JET LEFT EXIT REGION DIVERGENCE AND MID LEVEL DIFLUENCE
AHEAD OF THE CLOSED CIRCULATION HAVE ALL WORKED TO DRIVE PRECIP
ACROSS MUCH OF THE CWA THIS AFTERNOON. RAINFALL AMOUNTS HAVE BEEN
IMPRESSIVE IN SPOTS AS THE AIRMASS IS SEMI-TROPICAL...FEATURING A
DEEP WARM CLOUD LAYER SUPPORTIVE (SATURATED UP TO 12KFT) OF SMALL
DROP FORMATION.

PER RADAR TRENDS...THE INITIAL BATCH OF ENHANCED RAINFALL ACROSS
THE SOUTHERN CWA CONTINUES TO MIGRATE NORTH AND WEAKEN...IN LINE
WITH A GRADUAL EXPECTED REALIGNMENT OF 700-500MB DEFORMATION
FORCING TOWARD AREAS ALONG AND NORTH OF M-68. BASED ON THIS
IDEA...HAVE UPPED POPS NORTH OF THE BRIDGE...WHILE ALSO EXPECTING
ADDITIONAL AREAS OF RAIN TO DEVELOP ACROSS NORTHERN LOWER...BUT
MAYBE NOT UNTIL AFTER 06Z WITH THE UPPER TROUGH SWINGS CLOSER.
EITHER WAY YOU SLICE IT...IT`S GOING TO RAIN AT TIMES FOR JUST
ABOUT ALL AREAS OVERNIGHT...AND THE GOING FORECAST REFLECTS THAT
JUST FINE. TEMPS MAY NEED A LITTLE TWEAKING...BUT OVERALL...
READINGS INTO THE 40S SHOULD WORK JUST FINE.

AS AN ASIDE...ALSO RE-INTRODUCED SOME FOG INTO THE FORECAST OVER
THE WATERS AND CLOSE TO THE COASTS BASED ON THE LATEST PRE-SUNSET
WEBCAM IMAGES...PARTICULARLY ACROSS THE STRAITS AND TOWARD THE TVC
AREA. THIS SHOULD ERODE WITH TIME AFTER 06Z WITH STRENGTHENING
NORTHERLY FLOW EXPECTED.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 449 PM EDT WED MAY 22 2013

MODERATE RAINFALL AHEAD OF THE WARM FRONT JUST ENTERING OUR SOUTHERN
FORECAST AREA CONTINUES TO FALL...WITH APPARENT TERRAIN OR CSI
INDUCED POCKETS AND SMALL LINES OF HEAVY RAINFALL DEVELOPING. 1 MILE
NORTH OF WELLSTON HAD 0.75 INCHES OF RAIN WHICH FELL IN ABOUT 45
MINUTES UNDER ONE OF THESE HEAVY POCKETS OF RAIN. RAIN SHOULD BEGIN
FILLING IN OVER EASTERN UPPER LATER TONIGHT...AS AN UPPER LEVEL WAVE
APPROACHES THE GREAT LAKES. THIS SHORTWAVE ENERGY AHEAD OF THIS
APPROACHING WAVE COMBINED WITH ANOTHER ROBUST AMOUNT OF MID-LEVEL
MOISTURE FROM THE GULF ALONG WITH UPPER LEVEL JET SUPPORT WILL
DEVELOP YET ANOTHER AREA OF MODERATE TO HEAVY RAINFALL OVER THE SAME
AREA THAT RECEIVED THE HIGHEST AMOUNTS ALREADY TODAY FOR EARLY
TOMORROW MORNING AND INTO THE AFTERNOON HOURS. WITH ANOTHER 1 TO 1.5
INCHES OF RAIN POSSIBLY FALLING AGAIN LATE TONIGHT INTO TOMORROW
EXPECT RIVERS TO REACH OR EXCEED FLOOD STAGE BY THE EVENING HOURS.

RAIN WILL BEGIN TO END THURSDAY AFTERNOON FROM NORTHWEST TO
SOUTHEAST...AS A LARGE AREA OF HIGH PRESSURE BEGINS TO BUILD INTO
NORTHERN MICHIGAN BEHIND THE DEPARTING LOW PRESSURE SYSTEM.
NORTHERLY WINDS BEHIND THIS SYSTEM WILL BE GUSTY AND BEGIN ADVECTING
COLDER AIR. WITH THE CLOUD COVER AND COLD AIR ADVECTING INTO
NORTHERN MICHIGAN...MODELS HAVE CONTINUED WITH THE DOWNWARD TREND OF
MAX TEMPERATURES FOR THE AFTERNOON HOURS. DROPPED MAX TEMPS TO ONLY
THE UPPER 40S TO LOW 50S ACROSS ALL OF THE FORECAST AREA FOR
THURSDAY AFTERNOON.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 449 PM EDT WED MAY 22 2013

OVERVIEW: FAIRLY BLOCKY FLOW PATTERN IN PLACE ACROSS THE CONUS TODAY
WITH CLOSED LOWS ALONG THE WEST COAST AND GREAT LAKES...SHARP
RIDGING THROUGH THE PLAINS. PATTERN IS FORECAST TO SLOWLY FLATTEN
OUT OVER THE NEXT SEVERAL DAYS AS UPSTREAM RIDGING GRADUALLY SPREADS
INTO THE GREAT LAKES THROUGH THE UPCOMING HOLIDAY. THIS SIGNALS
REBOUNDING TEMPERATURES AND BASICALLY A STRETCH OF DRY WEATHER
THROUGH THE MEMORIAL DAY HOLIDAY AND MOST...IF NOT ALL OF THE
EXTENDED. ONLY REAL FORECAST CONCERNS WILL BE FROST/FREEZE POTENTIAL
FOR SEVERAL MORNINGS AS HIGH PRESSURE/LIGHT WINDS SETTLES INTO THE
GREAT LAKES.

IN THE NEARER TERM...THURSDAY NIGHT...SHARP TROUGH AXIS AND DEEPER
MOISTURE EXPECTED TO BE JUST SWINGING DOWN AND OUT OF THE THE REGION
BY THURSDAY EVENING...WITH A BROAD AREA OF CANADIAN HIGH PRESSURE
QUICKLY BUILDING DOWN INTO THE GREAT LAKES...CLEARING SKIES AND
RESPECTABLE COLD ADVECTION UNDERWAY. WE DO MAINTAIN A BIT OF A
GRADIENT AND NORTHERLY WIND THROUGH MUCH OF THE NIGHT...ESPECIALLY
OVER THE EASTERN HALF OF THE CWA...WHICH MAY BE ENOUGH TO PRECLUDE
THE DEVELOPMENT OF WIDESPREAD FROST. TEMPS WILL DIP INTO THE LOWER
30S INLAND BY VIRTUE OF COLD ADVECTION ALONE. BUT AGAIN...WITH A
LIGHT NORTHERLY FLOW...DON/T THINK WIDESPREAD TEMPS BELOW 32F WILL
BE ATTAINED EITHER. SO...AT THIS JUNCTURE...WILL HAVE PATCHY TO
AREAS OF FROST IN THE FORECAST...BUT NO FREEZE WATCH HEADLINES AT
THIS POINT.

FRIDAY THROUGH SUNDAY...NOT OFTEN WE GET TO LUMP THREE DAYS TOGETHER
IN A FORECAST DISCUSSION. LARGE EXPANSE OF CANADIAN HIGH PRESSURE
BUILDS DOWN THROUGH THE GREAT LAKES BY FRIDAY THEN REMAINS PRETTY
MUCH IN PLACE THROUGH THE WEEKEND. ANTICIPATE OVERALL SUNNY DAYS AND
MAINLY CLEAR NIGHTS. TEMPS START ON THE COOLER...BELOW NORMAL SIDE
OF THINGS FRIDAY WITH HIGHS MAINLY IN THE 50S. FRIDAY NIGHT LOOKING
LIKE THE BEST "WIDESPREAD" FROST NIGHT WITH LIGHT WINDS/MAINLY CLEAR
SKIES AND SUSPECT WE WILL NEED ANOTHER ROUND OF FROST HEADLINES
FRIDAY NIGHT...AND PERHAPS EVEN SATURDAY NIGHT AS WELL WITH LOW
TEMPS DIPPING DOWN IN THE LOWER TO MIDDLE 30S BOTH NIGHTS. DAYTIME
TEMPS WILL GRADUALLY REBOUND THROUGH THE 60S FOR SATURDAY AND
SUNDAY. NOT NECESSARILY THE WARMEST...BUT STILL A GREAT WEEKEND WITH
ABUNDANT SUN.

MONDAY THROUGH WEDNESDAY...AS MENTIONED ABOVE...RIDGING ACROSS THE
PLAINS EXPECTED TO SLOWLY ADVANCE EASTWARD INTO THE GREAT LAKES AND
ULTIMATELY THE EASTERN CONUS BY LATE NEXT WEEK. THE RESULT...WARMING
TREND FOR THE FIRST HALF OF NEXT WEEK WITH TEMPS REACHING AND
EVENTUALLY EXCEEDING CLIMO (LOWER 70S). DRY WEATHER FOR MEMORIAL DAY
AND TUESDAY (ENJOY). HOWEVER...GUIDANCE HAS BEEN HINTING AT THE
POSSIBILITIES FOR CONVECTIVE DEVELOPMENT ALONG THE FRINGE OF THE
RIDGE THROUGH THE PLAINS...POTENTIALLY IMPACTING THE GREAT LAKES
LATE BY WEDNESDAY AND POSSIBLY EVEN TUESDAY NIGHT. GFS IS MOST
BULLISH ON THIS IDEA. HAVE CHANCE POPS FOR WEDNESDAY AT THIS POINT
AND WILL REFINE AS WE GO ALONG.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1156 PM EDT WED MAY 22 2013

PERIODS OF RAIN WILL CONTINUE AT ALL TERMINAL SITES THE REMAINDER
OF THE NIGHT...AS WILL PERIODIC IFR CONDITIONS. HOWEVER...CEILINGS
AND VISIBILITIES WILL SHOW A RATHER RAPID IMPROVEMENT FROM NORTH
TO SOUTH AS NORTHERLY WINDS INTENSIFY AFTER 08Z AND HELP DRAG
DRIER AIR INTO THE AREA...LIFTING CEILINGS UP TOWARD MVFR OR EVEN
LOW END VFR. THAT TREND WILL CONTINUE THROUGH MIDDAY OR EARLY
AFTERNOON AS SKIES CLEAR COMPLETELY WHILE WINDS GET A LITTLE GUSTY
UP TO 20-25 KNOTS FOR A TIME. THINGS WILL CALM DOWN INTO THE
EVENING AS HIGH PRESSURE ARRIVES...WITH CLEAR SKIES AND WINDS
DROPPING TO 10 KNOTS OR LESS.


&&

.MARINE...
ISSUED AT 1156 PM EDT WED MAY 22 2013

UPDATE: MOST OF THE DENSE FOG HAS LIFTED THE PAST FEW HOURS AS
NORTHERLY WINDS BEGIN TO STRENGTHEN AND DRAG IN SOME DRIER AIR
WITH TIME. ALSO...HAVE DECIDED AGAINST GALES LATER TONIGHT INTO
THE DAYLIGHT HOURS. COULD SEE A BRIEF WINDOW OF 35 KNOT GUSTS BUT
JUST DON`T THINK IT WILL BE WIDESPREAD OR LONG ENOUGH TO JUSTIFY A
GALE AT THIS TIME.

EARLIER DISCUSSION:

DENSE FOG HAS BEGUN TO ERODE AS RAIN HAS OVERSPREAD THE ENTIRE
FORECAST AREA. GUSTY NORTHERLY WINDS WILL DEVELOP AS A TIGHT
PRESSURE GRADIENT SETS UP BEHIND THE DEPARTING LOW PRESSURE SYSTEM
AND AN AREA OF STRONG HIGH PRESSURE BUILDING IN FROM THE NORTHWEST
TOMORROW MORNING AND INTO THE AFTERNOON HOURS. WINDS WILL BE NEAR
OR JUST AT GALE FORCE FROM PRESQUE ISLE LIGHT SOUTH ON THE LAKE
HURON SHORELINE. EXPECT SMALL CRAFT WINDS ELSEWHERE. WINDS WILL
BEGIN TO SUBSIDE LATE TOMORROW AFTERNOON.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LHZ345>349.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ323-341-
     342-344>346.
LS...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LSZ321-322.

&&

$$

UPDATE...SD
SYNOPSIS...KB
SHORT TERM...TL
LONG TERM...BA
AVIATION...LAWRENCE
MARINE...TL