Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 281413
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1013 AM EDT THU MAY 28 2015

.UPDATE...
ISSUED AT 1012 AM EDT THU MAY 28 2015

SUN-FILLED SKIES ALLOWING TEMPERATURES TO RESPOND NICELY
THIS MORNING...WITH READINGS STILL EXPECTED TO REACH WELL INTO THE
70S AWAY FROM THE BIG WATERS THIS AFTERNOON. PLENTY OF QUESTIONS
REMAIN WITH AFTERNOON CONVECTIVE POTENTIAL...LARGELY HINGING ON HOW
DEW POINTS RESPOND. MOST HIGH RES GUIDANCE THAT KICKS OFF CONVECTION
SIMPLY HAS UNREALISTICALLY HIGH LOW LEVEL MOISTURE VALUES...WITH THE
NAM-WRF MID 60 DEW POINTS (SIMPLY UNATTAINABLE) LEADING THE CHARGE.
MODIFYING 12Z LOCAL SOUNDINGS SUPPORTS DEW POINTS MIXING OUT INTO
THE LOWER/MID 50S...AND WHEN COMBINED WITH ASSUMED STRENGTHENING OF
MID LEVEL CAPPING VIA BUILDING MID LEVEL HEIGHTS...SUPPORTS UPWARDS
OF SEVERAL HUNDRED JOULES/KG OF ML CAPE...ALONG WITH SOME LINGERING
CINH. SYNOPTIC WIND COMPONENT WILL REMAIN LIGHT OUT OF THE
SOUTHEAST...SUPPORTING FORCED LAKE HURON INDUCED CONVERGENCE INTO
THE EASTERN SECTIONS OF THE INTERIOR HIGHLANDS. THIS MAY BE JUST
ENOUGH TO OVERCOME OTHER DEFICIENCIES...ALLOWING SCATTERED/ISOLATED
SHOWERS/STORMS TO DEVELOP THIS AFTERNOON...WITH ATTENDANT OUTFLOW
BOUNDARIES DICTATING FUTURE DEVELOPMENT. INHERITED FORECAST LARGELY
TRENDED TOWARD THIS IDEA...WITH FEW CHANGES NEEDED. WILL CONTINUE TO
MONITOR MIXING/DEW POINT TRENDS THROUGH EARLY THIS AFTERNOON. ANY
STORMS THAT DO FORM SHOULD REMAIN BELOW SEVERE LIMITS...ALTHOUGH
ANTICIPATED SLOW MOVEMENT WOULD SUPPORT SOME LOCALLY HEAVY
RAINFALL.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 143 AM EDT THU MAY 28 2015

...LAKE BREEZES AND A COUPLE OF SHOWERS/STORMS...

SYNOPTIC PATTERN AND OBSERVATIONS:

EARLY THIS MORNING...NOT MUCH HAS CHANGED FROM THE EXPECTATIONS FROM
24 HRS AGO. AN ILL-DEFINED SFC TROUGH AND STEEP LAPSE RATES AXIS
ALOFT HAS SLIPPED INTO THE REGION. THE TROUGH IS ILL-DEFINED DUE TO
EARLIER LAKE BREEZES FROM CENTRAL UPPER AND NE WISCONSIN...AND LIGHT
WINDS FROM ADVANCING HIGH PRESSURE. SCATTERED SHOWERS AND STORMS HAD
FIRED OFF IN THESE AREAS...AND THE MEAN STORM LAYER FLOW WAS
DIRECTING THEM TOWARD NW LOWER...GENERALLY LEELANAU COUNTY AND AREAS
SOUTH. THERE WAS AN IDENTIFIABLE VERY WEAK VORT MAX THAT MAY HAVE
BEEN HELPING SUSTAIN THESE STORMS...BUT THIS WAS GETTING WASHED OUT
DUE TO INCREASING HEIGHT RISES. PLUS...WANING DIURNAL INSTABILITY
AND STORMS MOVING INTO LESS UNSTABLE ENVIRONMENT HAVE PROVED
EFFICIENT AT ALLOWING THIS AREA OF PRECIPITATION TO DWINDLE AND
WEAKEN OVER THE LAST SEVERAL HOURS. SKIES WERE GRADUALLY BECOMING
CLEARER...AND TEMPERATURES WERE DROPPING INTO/THROUGH THE 50S.

SYNOPTIC PATTERN EVOLUTION AND ASSOCIATED WEATHER:

FEEL AS IF THE SCATTERED SHOWERS/STORMS WILL BE LONG GONE AND ERODED
BY DAYBREAK....AND THE DAY STARTS OFF RELATIVELY CLEAR. THE SFC HIGH
PRESSURE WILL BE DIRECTLY OVERHEAD THIS MORNING...BEFORE GRADUALLY
SHIFTING EAST LATER TODAY INTO TONIGHT. GRADIENT WINDS WILL BECOME
LIGHT OUT OF THE SOUTHEAST HEADING THROUGH THE DAY WITH PEAK
AFTERNOON HEATING BRINING LAKE BREEZES WITH THE MAXIMIZED WIND
CONVERGENCE AGAINST THE EASTERN HIGHER TERRAIN...EXTENDING WESTWARD
BACK OVER TO ROUGHLY US 131...OR SLIGHTLY FURTHER WEST. DAYTIME
TEMPERATURES RISING WELL INTO THE 70S IN NRN LOWER WITH SFC TD`S
MIXING OUT TO 53F-55F RESULTS IN 1000-1200 J/KG. ISOLATED-SCATTERED
SHOWERS AND STORMS WILL FIRE OFF IN THE LOW LEVEL LAKE BREEZE
CONVERGENCE...AND THEN CONGEAL MORE SO INTO THE HIGHER TERRAIN...BUT
INDIVIDUAL STORM OUTFLOWS ARE LIKELY TO KEEP A FAIRLY LARGE AREA OF
INLAND NRN LOWER UNDER THE GUN FOR ADDITIONAL SHOWERS THROUGH
EVENING. LOCALLY HEAVY RAINFALL IS DEFINITELY POSSIBLE...AS
EFFECTIVE WIND SHEAR IN THE 0-10KM LAYER IS ROUGHLY 10KTS...THUS
SLOW MOVING CELLS ARE EXPECTED...DRIFTING NE. SOME OF THESE NE
MOVING STORMS ARE LIKELY TO PENETRATE FAR NRN LAKE HURON AND
POSSIBLY EVEN DRUMMOND ISLAND LATER THIS EVENING. NOWHERE ELSE IN
EASTERN UPPER IS EXPECTED TO SEE STORMS...AS THERE THE SE WIND IS
RATHER UNFAVORABLE...AND TEMPS WILL ONLY REACH THE LOW 70S WHICH
WILL LIMIT THE INSTABILITY. COVERAGE OF SHOWERS WILL WANE AFTER
NIGHTFALL. SKIES WILL THEN CLEAR THROUGH THE OVERNIGHT HOURS AS FCST
SOUNDINGS DO SHOW PRETTY DEEP DRYING.

SEVERE STORMS NOT EXPECTED...BUT WILL CERTAINLY NEED TO HAVE A
WATCHFUL EYE ON STRONGER CELLS. LOCALLY HEAVY RAINFALL THE BIGGEST
THREAT.

&&

.SHORT TERM...(FRIDAY THROUGH SATURDAY NIGHT)
ISSUED AT 143 AM EDT THU MAY 28 2015

HIGH IMPACT WEATHER POTENTIAL: THUNDERSTORMS POSSIBLE FRIDAY
AFTERNOON INTO LATE FRIDAY EVENING. THERE DOES APPEAR TO BE AT LEAST
A SMALL RISK FOR SOME OF THOSE TO BECOME SEVERE.

WELL...BACK WE GO INTO AN ACTIVE WEATHER REGIME TO WRAP UP THE WORK
WEEK...BEFORE THINGS REALLY CALM DOWN (AND COOL DOWN!) INTO THE
WEEKEND. AS HAS BEEN WELL ADVERTISED FOR SEVERAL DAYS NOW...SHARP
UPPER TROUGHING DIGGING THROUGH MANITOBA/SASKATCHEWAN IS EXPECTED TO
GRADUALLY DRIVE A FAIRLY SIGNIFICANT COLD FRONT INTO NORTHERN
MICHIGAN FRIDAY NIGHT...WITH A PRONOUNCED AXIS OF HEAT AND HUMIDITY
ARRIVING IN THE THERMAL RIDGE AHEAD OF THIS FEATURE. EXACT TIMING OF
THE FRONT STILL REMAINS SLIGHTLY IN QUESTION...THOUGH THE OVERALL
TREND OF LATE IS FOR A SLIGHTLY SLOWER EVOLUTION TO THE PATTERN...
SUGGESTING WE MAY HAVE A DECENT SHOT TO REALLY HEAT UP AND MOISTEN
UP PRIOR TO FRONTAL PASSAGE.

WHILE UPPER FORCING COULD BE BETTER (THE MAJORITY OF BEST QG UPWARD
SUPPORT LIFTS TO OUR NORTH)...WEAK HEIGHT FALLS IN COMBINATION WITH
STRONG LOW LEVEL FRONTAL CONVERGENCE SHOULD BE ENOUGH TO FIRE OFF A
BAND OF CONVECTION TO OUR WEST INTO THE AFTERNOON...WITH THE
REMNANTS OF THIS ACTIVITY PUSHING IN OUR DIRECTION INTO THE EVENING.
IN ADDITION...TURNING OF THE WINDS ONSHORE NEAR THE USUAL SUSPECT
SPOTS AS A PSEUDO-WARM FRONT GETS STUCK NEAR THE STRAITS SUGGESTS WE
MAY SEE A BIT OF PRE-FRONTAL CONVECTION AS WELL WHERE WE MAY LOCALLY
BREAK INITIAL CAPPING. INSTABILITY ON PAPER AT LEAST LOOKS RATHER
DECENT...WITH TEMPS RISING WELL INTO THE 70S AND LOW (MID?) 80S
PENDING NO CLOUD ISSUES WHILE BOUNDARY LAYER DEW POINTS SNEAK BACK
THROUGH THE MID OR PERHAPS EVEN UPPER 60S BASED ON UPSTREAM
READINGS. MID LEVEL LAPSE RATES LOOK BETTER THAN IN RECENT DAYS...
WITH FORECAST RAOBS HINTING AT UPWARDS OF 1500 J/KG MLCAPE. THROW IN
THE ARRIVAL OF STRONGER MID LEVEL FLOW INTO THE AFTERNOON AND AN
UPTICK IN EFFECTIVE SHEAR TOWARD 30-35 KNOTS AND THE STAGE IS SET
FOR AT LEAST A MARGINAL RISK FOR SEVERE STORMS DURING THE AFTERNOON
AND EVENING. THE MAIN THREATS WOULD BE DAMAGING WINDS AND PERHAPS TO
A LESSER DEGREE HAIL...THOUGH HIGH FREEZING LEVELS IN EXCESS OF
12KFT ARGUE THAT THREAT WILL BE DEPENDENT ON STRONGER UPDRAFTS.
CERTAINLY A PERIOD TO WATCH.

WHILE THE CONVECTIVE THREAT SHOULD END LATER FRIDAY NIGHT...
PERSISTENT STRONG AND DEEPER LAYER FRONTOGENESIS LAYING OUT ACROSS
THE AREA AND THE APPROACH OF ANOTHER WELL-MODELED SECONDARY TROUGH
AXIS STRONGLY SUGGESTS A BAND OF RAIN TRAVERSING THE AREA THROUGH AT
LEAST SATURDAY MORNING. EXACT ENDING TIME OF THIS PRECIP BAND
REMAINS SOMEWHAT PROBLEMATIC...BUT MY GUT FEELING IS THAT IT WILL
INCREASINGLY BE SUPPRESSED SOUTHWARD WITH TIME AS STRONG LOW LEVEL
RIDGING AND DRYING WORK IN FROM ONTARIO THROUGH THE DAY. THAT SHOULD
(THEORETICALLY) LEAD TO CLEARING SKIES RATHER QUICKLY FROM NORTH TO
SOUTH...WITH MOST IF NOT ALL AREAS JUST PLAIN CLEAR BY EVENING AND
INTO THE NIGHT. STILL QUITE A BIT OF FLOW JUST OFF THE DECK AND A
DECENT GRADIENT TO THEORETICALLY PREVENT WIDESPREAD COLD TEMPS/
FROST...BUT STILL CHILLY WITH TEMPS DOWN INTO THE 30S TO LOW 40S.
WILL CONTINUE A FROST MENTION JUST IN CASE SOME LOCALIZED SPOTS
DECIDE TO DECOUPLE...BUT REALLY THINK THE BETTER RISK COMES SUNDAY
NIGHT.

&&

.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 143 AM EDT THU MAY 28 2015

ABOUT AS QUIET AS IT GETS AROUND THESE PARTS AS WE WRAP UP THE
WEEKEND AND WELCOME THE NEW WORK WEEK...COURTESY OF ROBUST LOW LEVEL
RIDGING EXTENDING FROM SOUTHEAST CANADA DOWN INTO THE GREAT LAKES
REGION. PLENTY OF DRY AIR TO GO AROUND DURING THE PERIOD...WITH SOME
DOWNRIGHT COMFORTABLE WEATHER ON TAP AS WE END THE MONTH OF MAY AND
ENTER THE FIRST FEW DAYS OF JUNE. SHOULD BE LOTS OF SUNSHINE EACH
DAY WITH SUCH DRY AIR IN PLACE...WITH INCREASINGLY WARMER BUT LOW
HUMIDITY AFTERNOONS AND SOME QUITE CHILLY OVERNIGHT TEMPS. BASED ON
THE PATTERN SETUP WITH THE RIDGE AXIS HANGING OVERHEAD RIGHT ON
THROUGH TUESDAY...HAVE NO DOUBT WE ARE LOOKING AT SEVERAL NIGHTS
WITH A FROST THREAT...WITH THE BEST POTENTIAL SUNDAY NIGHT GIVEN A
VERY WEAK GRADIENT IN PLACE...THOUGH COULD ALSO ENVISION ANOTHER
NIGHT WITH SOME PATCHY FROST MONDAY NIGHT AS WELL. MAYBE JUST MAYBE
WE CAN MUSTER SOME BETTER RETURN FLOW TOWARD WEDNESDAY WITH A LOW
END THREAT FOR SOME SHOWERS TO MAKE A RETURN.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 602 AM EDT THU MAY 28 2015

...SHOWERS AND STORMS BETWEEN THE AIRPORTS THIS AFTERNOON AND
EVENING...

HIGH PRESSURE THIS MORNING WILL SHIFT EAST LATER TODAY AND
TONIGHT RESULTING IN A LIGHT SE FLOW THAT WILL TURN ONSHORE THIS
AFTERNOON. THE RESULTING LAKE BREEZE CONVERGENCE WILL SET UP
PRIMARILY BETWEEN THE NW LOWER AIRPORTS AND APN. SCATTERED SHOWERS
AND STORMS WILL FIRE OFF HERE...AND TRACK GENERALLY NE...LIKELY
NOT AFFECTING ANY AIRPORT...BUT MAY BE CLOSE TO TVC/PLN FOR VCSH
WORDING. SHOWERS AND STORMS WILL CONTINUE THROUGH THE EVENING
BEFORE WANING AROUND MIDNIGHT. FAIRLY DEEP DRYING WILL CLEAR OUT
THE SKIES FOR THE OVERNIGHT. SOME LIGHT FOG WILL BE POSSIBLE...BUT
INCREASING WINDS ALOFT WITH THE DEVELOPMENT OF LLWS WILL LIKELY
LIMIT THAT.


&&

.MARINE...
ISSUED AT 143 AM EDT THU MAY 28 2015

SFC HIGH PRESSURE IS SLIDING IN OVERHEAD...BUT WILL EXIT EAST LATER
TODAY THROUGH TONIGHT. A LIGHT SE FLOW DEVELOPS...WHICH WILL TURN
ONSHORE THIS AFTERNOON. SCATTERED SHOWERS AND STORMS WILL LIKELY
LIFT INTO FAR NRN LAKE HURON LATE THIS AFTERNOON INTO THE EVENING
HOURS BEFORE WANING. WINDS INCREASE ABOVE THE STABLE MARINE SFC LATE
TONIGHT...BUT LIKELY NOT TO ADVISORY LEVELS. A COLD FRONT APPROACHES
THE WESTERN GREAT LAKES FRIDAY AND IT COULD GET A LITTLE GUSTY...BUT
WITH IT`S PASSAGE FRIDAY NIGHT...THE GREATEST CHANCE FOR ADVISORIES
WILL BE THEN...SATURDAY AND EVEN SATURDAY NIGHT. SUNDAY MAYBE AS
WELL...AS OVERLAKE STABILITY CONTINUES TO WEAKEN.


&&

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

$$

UPDATE...MSB
NEAR TERM...SMD
SHORT TERM...LAWRENCE
LONG TERM...LAWRENCE
AVIATION...SMD
MARINE...SMD



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