Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 311757
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
157 PM EDT THU JUL 31 2014

.SYNOPSIS...
ISSUED AT 403 AM EDT THU JUL 31 2014

WEAK UPPER LEVEL DISTURBANCES ROTATING ACROSS THE REGION WILL
CONTINUE TO BRING PERIODIC SMALL CHANCES FOR SHOWERS THROUGH
SATURDAY...ESPECIALLY DURING THE AFTERNOON HOURS AND MAINLY
ACROSS NORTHEAST LOWER MICHIGAN. MOST LOCATIONS...HOWEVER...WILL
REMAIN RAIN FREE. DRY WEATHER RETURNS FOR ALL AREAS TO END THE
WEEKEND...WITH THE THREAT FOR A FEW MORE SHOWERS TO START NEXT
WORK WEEK. TEMPERATURES WILL FINALLY MAKE A RETURN TO MUCH MORE
SEASONAL LEVELS FRIDAY...CONTINUING THROUGH THE EXTENDED.

&&

.UPDATE...
ISSUED AT 1004 AM EDT THU JUL 31 2014

GOING FORECAST IN GOOD SHAPE HEADING INTO THE AFTERNOON...WITH NO
BIG CONCERNS...MINUS THE POTENTIAL FOR A FEW POPUP NUISANCE
SHOWERS. 12Z APX RAOB SHOWS A GRADUAL CHANGE IN OUR LOW LEVEL
AIRMASS OVER THE PAST 24 HOURS...WITH SLIGHT WARMING SEEN...WHILE
MUCH MORE PRONOUNCED WARMING IS NOTED ALOFT ABOVE 600MB. THE BASIC
UPPER PATTERN REMAINS THE SAME (REALLY NOT MUCH DIFFERENT FROM
THAT NOTED A GOOD CHUNK OF THE "SUMMER")...FEATURING QUITE THE
CLOSED UPPER LOW MEANDERING IN THE VICINITY OF JAMES BAY. THAT
PATTERN CONTINUES TO SEND THE OCCASIONAL WEAK SHORTWAVE/SURFACE
TROUGH IN OUR DIRECTION...AND INDEED ANOTHER SUCH TROUGH IS SEEN
PIVOTING SOUTHWARD ACROSS NORTHERN LAKE SUPERIOR. THAT FEATURE
SHOULD ARRIVE ACROSS THE EASTERN U.P. JUST ABOUT THE TIME OF PEAK
HEATING...WORKING IN COMBINATION WITH WHAT SHOULD BE DECENT INLAND
LAKE BREEZE CONVERGENCE TO HELP FIRE OFF A COUPLE OF SHOWERS UP
THAT WAY...WITH ANY SUCH ACTIVITY NOTING A SLIGHT SOUTHEAST DRIFT
PER THE STEERING FLOW. INSTABILITY IS MEAGER AT BEST...ESPECIALLY
WITH THE NOTED WARMING ALOFT...THOUGH WITH TEMPS INTO THE LOW 70S
AND DEW POINTS PERHAPS TOUCHING THE LOW 50S IN SAID CONVERGENCE...
WE CAN PROBABLY SQUEEZE OUT 100-200 J/KG UP THAT WAY - ENOUGH FOR
ISOLATED SHOWERS TO WORK WITH.

A SIMILAR SETUP IS SEEN ACROSS THE EASTERN CWA AS WELL...THOUGH
MUCH LIKE YESTERDAY...GET THE FEELING ANY DIURNAL ACTIVITY WILL
BE RELEGATED TO AREAS CLOSER TO THE COAST AS LAKE BREEZE INLAND
PENETRATION WON`T BE ANYTHING GREAT. IN ADDITION...HAVING A HARD
TIME BUYING INTO WIDESPREAD DEW POINTS INTO THE MID OR UPPER 50S
AS SUGGESTED BY THE MAJORITY OF GUIDANCE. INSTEAD...SOMETHING MORE
LIKE THE LOW 50S MAY GIVE A FEW HUNDRED JOULES AT BEST...SO HAVE
REWORKED POPS JUST A TOUCH TO SHOW MORE OF A "NEAR COAST" LOOK TO
THINGS. MEANWHILE...NOT MUCH OF ANYTHING IS FORESEEN ACROSS
NORTHWEST LOWER WHERE A PRONOUNCED LAKE SHADOW WILL RESIDE IN
BACKGROUND WESTERLY FLOW. TEMPS COULD PERHAPS STAND TO BE RAISED A
COUPLE DEGREES IN EASTERN UPPER WHERE SKIES HAVE CLEARED EARLIER
THAN EXPECTED...BUT WITH ANOTHER BATCH OF THICKER MID CLOUD
LURKING OVER SUPERIOR...WILL GIVE THE COOLER READINGS A CHANCE TO
PLAY OUT FOR A FEW MORE HOURS.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 403 AM EDT THU JUL 31 2014

...A SIMILAR DAY WITH A FEW MORE SHOWERS...

IMPACTS: NONE.

CURRENT WEATHER AND SYNOPTIC PATTERN:

DEEP CLOSED UPPER LOW STILL CIRCLING NEAR JAMES BAY WITH SEVERAL
VORTICITY MAXIMA ROTATING AROUND THE GYRE. ONE OF THE STRONGER VORT
MAXIMA WAS PUSHING EAST OF US EARLY THIS MORNING...ALONG WITH THE
ASSOCIATED SFC TROUGH. A WEAKER WAVE...ONLY NOTED ON SOME OF THE
HIGHER RESOLUTION DATA IS QUICKLY FOLLOWING...AND DRIVING THE
LAST VESTIGES OF LIGHT SHOWERS OUT OF NE LOWER. FURTHER UPSTREAM IN
THE NNW FLOW ALOFT...A MUCH WEAKER VORT MAX IS DROPPING SE FROM SW
ONTARIO...AND IS ASSOCIATED WITH JUST ANOTHER IN A SERIES OF RECENT
SFC TROUGHS. THIS SFC TROUGH IS ALIGNED FROM JAMES BAY THROUGH
CENTRAL LAKE SUPERIOR...WITH MQT/APX VAD WIND PROFILES SHOWING
BACKING LOW LEVEL WINDS. THERE WERE SOME SHOWERS ASSOCIATED WITH
THESE FEATURES YESTERDAY AFTERNOON...WITH NO THUNDER...AS LAPSE
RATES WERE LESS WITHOUT A STRONGER WAVE ALOFT. ALSO...MORE
WIDESPREAD AND DEEPER MOISTURE IS SEEN ACROSS ONTARIO...WORKING
SOUTHWARD INTO EASTERN UPPER. THE BETTER LOW LEVEL WINDS/MOISTURE
AND STEEPER LAPSE RATES/INSTABILITY GRADIENT RESIDE WELL WEST ACROSS
MN/WISCONSIN.

SYNOPTIC PATTERN/WEATHER EVOLUTION:

LOW TO MID LEVEL NORTHERLY FLOW WILL CONTINUE TO WRAP DEEPER
MOISTURE FROM ONTARIO DOWN AND ACROSS EASTERN UPPER THIS MORNING
INTO EARLY AFTERNOON. THIS MAY KEEP OVERALL BL HEATING AND RESULTANT
INSTABILITY AT BAY. LESS CLOUDS ACROSS NRN LOWER AND SLIGHTLY WARMER
LOW LEVEL TEMP REGIME THAN YESTERDAY. BL MOISTURE REMAINS
UNIMPRESSIVE...BUT MODIFICATION OF FCST BFR SOUNDINGS DO REVEAL A
FEW HUNDRED J/KG SNEAKING BY A WEAK CAP AT 650MB. FROM A FORCING
PERSPECTIVE...AFOREMENTIONED WEAKER VORT MAX AND SFC TROUGH DO TRY
AND ROTATE SOUTHWARD INTO EASTERN UPPER THIS AFTERNOON...AND IS
QUITE WEAK. THOUGH WINDS ARE LIGHT AND DIFFICULT TO DISCERN THE SFC
TROUGH...IT APPEARS TO PUSH THROUGH NRN LOWER THIS EVENING/TONIGHT.
LOW LEVEL WINDS ARE LIGHT...AND LAKE BREEZES TODAY WILL DISRUPT LOW
LEVEL CONVERGENCE WITH THE TROUGH...BUT ALSO CREATE ANOTHER DAY OF
LAKE BREEZE CONVERGENCE ACROSS INTERIOR EASTERN UPPER AND NE LOWER.
PUT ALL THIS TOGETHER...AND BELIEVE THAT OVERALL SHOWER ACTIVITY
WILL BE LESS THAN YESTERDAY. ISOLATED LIGHT SHOWERS ACROSS INTERIOR
EASTERN UPPER...WITH ISOLATED TO SCATTERED ACTIVITY EAST OF I-75 AND
MOST COMMON ACROSS FAR NE LOWER. THE PASSING OF THE MID LEVEL TROUGH
AND WEAK SFC TROUGH TONIGHT...RESULTING IN A FEW ROAMING SHOWERS IN
NRN LOWER.

HIGH TEMPERATURES NEAR 70F IN EASTERN UPPER WITH THE LOWER HALF OF
THE 70S IN NRN LOWER. LOWS TONIGHT AGAIN IN THE UPPER 40S AND LOWER
50S.

&&

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 403 AM EDT THU JUL 31 2014

...TEMPERATURES MUCH CLOSER TO NORMAL WITH A FEW LINGERING SHOWER
CHANCES...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: CURRENT UNSEASONABLY DEEP
EAST NOAM TROUGHING WILL BEGIN TO RELAX SOME HEADING INTO THE END OF
THE WEEK...LEADING TO A MUCH LESS AMPLIFIED VERSION OF ITSELF
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. THAT SAID...SOME
SEMBLANCE OF GREAT LAKES TROUGHING WILL REMAIN...ENSURING NO REAL
SUSTAINED SUMMER HEAT ANYTIME IN THE FORESEEABLE FUTURE. STILL A FEW
VORT LOBES/LOW AMP SHORTWAVES TO PASS THROUGH THIS DEAMPLIFYING
TROUGH...AND WHEN COMBINED WITH THE DIURNAL INSTABILITY CYCLE/LAKE
INDUCED CONVERGENCE AXES...CONTINUES TO SUPPORT MAINLY AFTERNOON
SHOWER POTENTIAL BOTH FRIDAY AND SATURDAY. NEXT WAVE LOOKS TO ARRIVE
EARLY NEXT WEEK...BRINGING ADDITIONAL SHOWER CHANCES.

PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE AND CLOUD TRENDS
THROUGHOUT. ACCESSING MAINLY AFTERNOON SHOWER POTENTIAL FOR THE
REMAINDER OF THIS WEEK. EARLY NEXT WEEK SHOWER CHANCES WILL ALSO
NEED ADDRESSING.

DETAILS: THOUGHT PROCESS HAS NOT CHANGED MUCH AT ALL FOR FRIDAY
THROUGH THE WEEKEND. PATTERN RECOGNITION CONTINUES TO SUPPORT
MAINLY AFTERNOON SHOWER DEVELOPMENT AS SAID WAVES INTERACT WITH THE
"PEAK" OF THE DAYTIME HEATING CYCLE. LOW LEVEL CONVERGENCE
BULLSEYE`S WILL BE THERE FOR A FOCUSING MECHANISM...SPECIFICALLY IN
THE FORM OF MAINLY LAKE HURON INDUCED LAKE BREEZES. LACK OF FORCING
AND RATHER LIMITED LOWER LEVEL MOISTURE (DEWPOINTS REMAINING MOSTLY
IN THE 50S) SHOULD KEEP SHOWER COVERAGE SCATTERED...AND PRECLUDE
MUCH OF A THUNDER THREAT. PATTERN FULLY SUPPORTS A STRONG APPROACH
TO TRADITIONAL NORTHERN MICHIGAN WARM-SEASON CONVECTIVE
CLIMATOLOGY...WITH A FULLY MATURE LAKE MICHIGAN SHADOW KEEPING
NORTHWEST LOWER DRY...WITH SAID LAKE HURON LAKE BREEZES/INLAND
THERMAL LOWS DRIVING BEST SHOWER CHANCES ACROSS NORTHEAST LOWER. MAY
SEE A FEW INTERIOR EASTERN UPPER SHOWERS WHERE LAKE INDUCED
CONVERGENCE IS MAXIMIZED...WITH OVERALL COVERAGE GREATLY LIMITED BY
EVEN MORE MEAGER LOW LEVEL MOISTURE. SUNDAY STILL APPEARS DRY...
COURTESY OF WARMING MID LEVELS PREVENTING ANY DECENT INSTABILITY
FROM BEING REALIZED.

RATHER REMARKABLE AGREEMENT NEXT MID LEVEL IMPULSE ARRIVES SUNDAY
NIGHT INTO MONDAY. THIS ONE LOOKS TO BE ACCOMPANIED BY A SLOWLY
SOUTH SAGGING COOL FRONT...WHICH SHOULD HELP DRIVE SOME BETTER LOW
LEVEL CONVERGENCE. FORCING FAR FROM OVERWHELMING AT THIS EARLY
JUNCTURE...BUT STILL ENOUGH SUPPORT THERE TO CONTINUE WITH INHERITED
LOW POP THEME. DRY WEATHER LOOKS TO FOLLOW INTO MID WEEK AS SURFACE
HIGH PRESSURE SETTLES OVERHEAD...ALL-THE-WHILE MID LEVEL DRY
NORTHWEST FLOW PERSISTS. OF COURSE...ALL OF THIS IS SUBJECT TO
CHANGE...ESPECIALLY WITH REGARDS TO TIMING. PLENTY OF TIME TO FIGURE
OUT THOSE SPECIFICS IN THE COMING DAYS.

TEMPERATURES: READINGS MUCH CLOSER TO WHAT ONE WOULD EXPECT TO START
AUGUST...WITH HIGH TEMPERATURES MOSTLY IN THE MID AND UPPER 70S
FRIDAY THROUGH MONDAY (JUST ABOUT AT NORMAL). POST-FRONTAL COOLING
TUESDAY AND WEDNESDAY IS NOTHING TOO ALARMING...WITH READINGS
PERHAPS A FEW DEGREES BELOW NORMAL.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 157 PM EDT THU JUL 31 2014

MAINLY VFR THROUGH THE PERIOD. SCATTERED TO BROKEN CUMULUS WILL
CONTINUE DEVELOPING THROUGH THE AFTERNOON...WITH EVEN A LONE
SHOWER POSSIBLE AROUND KAPN. A FEW MORE CLOUDS MAY DRIFT THROUGH
THE REGION OVERNIGHT...BUT NOTHING MAJOR. LIGHT FLOW MAY AGAIN
ALLOW FOR SOME SHALLOW GROUND FOG DEVELOPMENT...MAINLY AFTER 08Z.
WINDS WILL BECOME INFLUENCED BY LAKE BREEZES AT ALL SITES THROUGH
THE AFTERNOON...BECOMING LIGHT/VARIABLE/CALM OVERNIGHT.

&&

.MARINE...
ISSUED AT 403 AM EDT THU JUL 31 2014

NO MARINE ISSUES TO BE CONCERNED WITH OVER THE NEXT SEVERAL DAYS.
WEAK PRESSURE GRADIENT AND RESULTANT WEAK WINDS BEING DOMINATED IN
THE AFTERNOON BY ONSHORE LAKE BREEZES. THIS THE PATTERN THROUGH
AT LEAST EARLY NEXT WORK WEEK. SCATTERED SHOWERS TO AFFECT
NEARSHORE WATERS AGAIN THIS AFTERNOON ACROSS FAR NRN LAKE
MICHIGAN...STRAITS AND LAKE HURON.

&&

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

&&

$$

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



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