5/10/14

Update 5/16/14; Temperatures Flirting Near Record Cold Into the Weekend

Update 5/16

Well below normal temperatures are firmly entrenched over Southeast Lower Michigan, some overnight lows were as much as 20 degrees below normal. Unfortunately; I don't have any better news into the weekend with temperatures still expected to fall into the lower 30s to lower 40s Saturday and possibly now, even Sunday. Scattered frost is also likely in open areas and away from the lakes and major cities. See the records I posted below under 5/14 update below as a reference. While I still feel most records will stay intact, there is the risk of falling in or near record territory at some locations over the weekend.

Take a look at the cold overnight lows Friday morning....

000
ASUS63 KDTX 161521
RTPDTX
MORNING TEMPERATURE AND PRECIPITATION SUMMARY
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1121 AM EDT FRI MAY 16 2014

VALUES REPRESENT YESTERDAY`S HIGHS....LOW OVER THE LAST 12 HOURS
AND PRECIPITATION OVER THE LAST 24 HOURS ENDING AT 8 AM EDT


.BR DTX  0516  ES DH00/TAIRZX/DH07/TAIRZP/TA/PPDRZZ


:SOUTHEAST MICHIGAN -- TEMPERATURE AND PRECIPITATION STATIONS
:.......................................................
:       STATION              MAX / MIN  / 8 AM  / 24-HR
:        NAME                TEMP/ TEMP / TEMP  / PRECIP
:.......................................................
WHKM4: NWS WHITE LAKE      :   54 /  31  /  36  / 0.37
123M4: ANN ARBOR           :   57 /  35  /  35  / 0.36
ADG  : ADRIAN AIRPORT      :   60 /  35  /  38  / 0.19
BAX  :*BAD AXE AIRPORT     :   48 /  37  /  40  /
CFS  :*CARO AIRPORT-TUSCOLA:   50 /  38  /  40  /
DET  : DETROIT CITY AIRPORT:   67 /  38  /  41  / 0.43
DTW  : DETROIT METRO ARPT  :   64 /  36  /  38  / 0.13
FNT  : FLINT BISHOP AIRPORT:   52 /  36  /  39  / 0.21
ONZ  :*GROSSE ILE AIRPORT  :   63 /  37  /  39  /
OZW  :*HOWELL AIRPORT      :   49 /  33  /  37  /
DUH  :*LAMBERTVILLE AIRPORT:   63 /  36  /  41  /
D95  :*LAPEER DUPONT AIRPRT:   51 /  35  /  37  /
IKW  :*MIDLAND AIRPORT     :   48 /  38  /  40  /
TTF  :*MONROE AIRPORT      :   63 /  36  /  39  /
RNP  :*OWOSSO AIRPORT      :    M /   M  /   M  /
PTK  : PONTIAC AIRPORT     :   56 /  34  /  37  / 0.34
P58  : PORT HOPE           :   49 /  37  /  38  / 0.33
PHN  :*PORT HURON AIRPORT  :   64 /  36  /  39  /
MBS  : SAGINAW - TRI-CITIES:   49 /  37  /  39  / 0.28
HYX  :*SAGINAW-HARRY BROWNE:   50 /  36  /  37  /
VLL  :*OAKLAND/TROY AIRPORT:   62 /  37  /  38  /
YIP  : YPSILANTI WILLOW RUN:   66 /  37  /  40  / 0.24
.END


*THE TEMPERATURE DATA FOR THESE SITES ABOVE REPRESENT THE HIGHEST AND
 LOWEST TEMPERATURES THAT WERE REPORTED ON THE METAR OBSERVATIONS
 THAT TRANSMIT THREE TIMES AN HOUR AND MAY NOT REPRESENT THE ACTUAL
 HIGH OR LOW FOR THAT SITE. THESE SITES DO NOT MEASURE
 PRECIPITATION.
.....................................................................


THE FOLLOWING COOPERATIVE OBSERVER SITES REPORT FROM MIDNIGHT TO
MIDNIGHT THE PREVIOUS DAY.


.BR DTX  0516  ES DH07/TAIRZX/TAIRZN/TA/PPDRZZ


:SOUTHEAST MICHIGAN -- TEMPERATURE AND PRECIPITATION STATIONS
:.......................................................
:       STATION               MAX / MIN  / 12 AM /24-HR
:        NAME                 TEMP/ TEMP / TEMP  /PRECIP
:.......................................................
ARNM4: ADRIAN              :   59 /  41  /  42  / 0.54
MILM4: MILFORD - GM GROUNDS:   54 /  41  /  41  / 0.63
MDLM4: MIDLAND             :   58 /  37  /  37  / 1.39
MTCM4: MT CLEMENS SELFRIDGE:   65 /  45  /  45  / 0.88
PRHM4: PORT HURON          :   64 /  43  /  46  / 0.94
SGNM4: SAGINAW 5W          :   48 /  37  /  37  / 1.58
.....................................................................


COOPERATIVE OBSERVATIONS VALUES ARE FOR APPROXIMATELY THE PREVIOUS 24
HOURS FROM YESTERDAYS OBSERVATION TIME TO TODAY`S OBSERVATION TIME.


.BR DTX  0516  ES DH07/TAIRZX/TAIRZN/TA/PPDRZZ


:SOUTHEAST MICHIGAN -- TEMPERATURE AND PRECIPITATION STATIONS
:.........................................................
:       STATION            OB   /MAX / MIN  / OB   /24-HR
:        NAME              TIME /TEMP/ TEMP / TEMP /PRECIP
:.........................................................
: ***MIDLAND COUNTY***


: ***BAY COUNTY***


: ***HURON COUNTY***
BDAM4:  BAD AXE           :0725/   48 /  37  /  38  / 0.33
FLNM4:  FILION 5NNW       :M   /    M /   M  /   M  / 0.26
POAM4:  PORT AUSTIN       :0747/   48 /  36  /  37  / 0.30
PHPM4:  PORT HOPE         :0800/   50 /  36  /  38  / 0.40


: ***SAGINAW COUNTY***
CHSM4:  CHESANING         :0730/      /      /      / 0.43
FKMM4:  FRANKENMUTH 1SE   :0740/   49 /  35  /  36  / 0.20
MERM4:  MERRIL 2E         :0800/   49 /  35  /  38  /    M
SAGM4:  SAGINAW           :0800/   48 /  35  /  37  / 0.38


: ***TUSCOLA COUNTY***
CARM4:  CARO              :0710/   56 /  35  /  36  / 0.25
VSSM4:  VASSAR            :0700/   50 /  36  /  37  / 0.34


: ***SANILAC COUNTY***
LEXM4:  LEXINGTON         :0725/   55 /  36  /  39  / 0.60
SANM4:  SANDUSKY          :0639/   53 /  36  /  37  / 0.40


: ***SHIAWASSEE COUNTY***
CORM4:  CORUNNA 2NE       :0600/   54 /  36  /  36  / 0.79
DRNM4:  DURAND            :0800/   49 /  34  /  37  / 0.21


: ***GENESEE COUNTY***
BUNM4:  BURTON 4N         :0700/   54 /  33  /  37  / 0.30
FLTM4:  FLINT  7W         :0800/   51 /  35  /  38  / 0.22
LIDM4:  LINDEN            :0720/   49 /  34  /  37  /    M
GODM4:  GOODRICH          :0730/   51 /  33  /  37  / 0.16


: ***LAPEER COUNTY***
LPEM4:  LAPEER 2W         :0900/   52 /  34  /  38  / 0.04
LPRM4:  LAPEER            :0730/   52 /  35  /  37  / 0.30


: ***ST. CLAIR COUNTY***
YALM4:  YALE              :0630/   59 /  35  /  37  / 0.47


: ***LIVINGSTON COUNTY***
HOWM4:  HOWELL            :0800/   52 /  34  /  39  / 0.31
WHLM4:WHITMORE LK 1N      :0700/   54 /  35  /  35  / 0.40


: ***OAKLAND COUNTY***
FARM4:  FARMINGTON        :0730/   59 /  34  /  36  / 0.25
PONM4:  PONTIAC           :1052/   57 /  35  /  43  / 0.02
WSBM4:  WEST BLOOMFIELD   :0615/      /       /     / 0.30


: ***MACOMB COUNTY***
RICM4:  RICHMOND 4NNW     :0800/   62 /  36  /  39  / 0.62


: ***WASHTENAW COUNTY***
AASM4: ANN ARBOR-SOUTHEAST:0730/   59 /  35  /  37  / 0.28
CHLM4:  CHELSEA           :0943/   52 /  34  /  42  / 0.02
MCHM4:  MANCHESTER        :0705/   56 /  33  /  34  / 0.36
SLNM4:  SALINE 4SW        :0900/   57 /  26  /  37  / 0.09
SALM4:  SALINE            :0815/   60 /  35  /  41  / 0.24


: ***WAYNE COUNTY***
DBNM4:  DEARBORN          :0600/   64 /  37  /  37  / 0.20
DRBM4:U OF M DEARBORN     :0900/   63 /  34  /  41  / 0.04
GPFM4:  GROSSE PTE FARMS  :0800/   64 /  36  /  39  / 0.59
WYTM4:  WYANDOTTE         :0800/      /       /     / 0.15


: ***LENAWEE COUNTY***
BLIM4:  BLISSFIELD        :0630/      /       /     / 0.18
MRIM4:  MORENCI           :0730/   60 /  32  /  35  / 0.27
TECM4:  TECUMSEH          :0630/   60 /  33  /  35  / 0.42
TIPM4:  TIPTON 2WNW       :0800/   58 /  33  /  38  / 0.26


: ***MONROE COUNTY***
DNDM4:  DUNDEE            :0700/   62 /  35  /  36  / 0.22
MLIM4:  MILAN             :0605/   62 /  35  /  35  / 0.26
MNRM4:  MONROE            :0900/   62 /  35  /  43  / 0.08
NWPM4:  NEWPORT 4SSE      :0700/   61 /  37  /  37  / 0.19
.END

 
Update 5/14

First things first; stormy weather over the past few days brought scattered damaging thunderstorm winds and flooding rains across Southeast Lower Michigan. Here is the Severe Weather Report for Tuesday, 5/13 from the NWS in White Lake /DTX/. None of the three "tornadoes" reported during Monday's (5/12) storms were ever confirmed.

Below this summary, is the rest of the week's outlook.

Severe Thunderstorm Summary for May 13, 2014

Severe thunderstorms developed ahead of a cold front on the afternoon of May 13, 2013. Storms raced east across most of Southeast Lower Michigan, causing a broad area of damage. Several trees and power lines were downed, along with reports of wind gust measurements ranging from 50 to 60 mph.


PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
610 PM EDT TUE MAY 13 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0232 PM     TSTM WND DMG     3 NW BRIGHTON           42.56N 83.83W
05/13/2014                   LIVINGSTON         MI   AMATEUR RADIO 

            THE TOP OF A 6 INCH DIAMETER TREE WAS BLOWN OFF.

0252 PM     TSTM WND DMG     3 ESE PINCKNEY          42.44N 83.90W
05/13/2014                   LIVINGSTON         MI   TRAINED SPOTTER

            TREES AND LARGE LIMBS DOWN

0254 PM     TSTM WND DMG     2 WNW ANN ARBOR         42.28N 83.77W
05/13/2014                   WASHTENAW          MI   LAW ENFORCEMENT

            HURON - DEXTER AND MAPLE STREETS...6 HOMES WITH
            STRUCTURAL DAMAGE.

0255 PM     TSTM WND DMG     4 SSW ANN ARBOR         42.23N 83.76W
05/13/2014                   WASHTENAW          MI   TRAINED SPOTTER

            3 INCH TREE LIMBS DOWNS ELLSWORTH AND LOHR

0258 PM     TSTM WND DMG     1 WSW ANN ARBOR         42.27N 83.75W
05/13/2014                   WASHTENAW          MI   PUBLIC        

            LARGE TREE UPROOTED AND FELL ON TOP OF DETATTACHED GARAGE
            AT MAIN AND KOCH ROADS

0302 PM     TSTM WND DMG     5 N YPSILANTI           42.32N 83.63W
05/13/2014                   WASHTENAW          MI   EMERGENCY MNGR

            NUMEROUS LARGE TREES DOWN ON WIRES.

0302 PM     TSTM WND DMG     UBLY                    43.71N 82.93W
05/13/2014                   HURON              MI   911 CALL CENTER

            DOWNED POWER LINES

0311 PM     FLOOD            FLINT                   43.02N 83.69W
05/13/2014                   GENESEE            MI   TRAINED SPOTTER

            MULTIPLE STREETS FLOODED- VEHICLES STRANDED NEAR ATHERTON
            AND HEMPHILL ROADS WEST OF SAGINAW STREET.

0311 PM     TSTM WND GST     4 ESE ANN ARBOR         42.26N 83.66W
05/13/2014  E65.00 MPH       WASHTENAW          MI   TRAINED SPOTTER

            NO REPORT OF DAMAGE AT THIS TIME.

0314 PM     TSTM WND GST     OXFORD                  42.82N 83.25W
05/13/2014  E60.00 MPH       OAKLAND            MI   TRAINED SPOTTER

            FENCE BLOWN OVER

0316 PM     TSTM WND GST     ROMULUS                 42.22N 83.37W
05/13/2014  M58.00 MPH       WAYNE              MI   ASOS          

0318 PM     TSTM WND DMG     FARMINGTON HILLS        42.49N 83.38W
05/13/2014                   OAKLAND            MI   BROADCAST MEDIA

            LARGE TREE DOWN. TIME ESTIMATED OFF RADAR.

0330 PM     TSTM WND DMG     3 S PETERSBURG          41.85N 83.71W
05/13/2014                   MONROE             MI   911 CALL CENTER

            POWER LINES DOWN

0332 PM     TSTM WND DMG     5 S DUNDEE              41.88N 83.67W
05/13/2014                   MONROE             MI   911 CALL CENTER

            LARGE TREE AND WIRES DOWN.

0336 PM     TSTM WND DMG     2 SSW IDA               41.88N 83.59W
05/13/2014                   MONROE             MI   911 CALL CENTER

            LARGE TREE AND POWER LINES DOWN

0337 PM     TSTM WND GST     CLINTON TOWNSHIP        42.59N 82.92W
05/13/2014  M61.00 MPH       MACOMB             MI   PUBLIC        

            VIA FACEBOOK

0338 PM     TSTM WND GST     1 ESE WARREN            42.49N 83.01W
05/13/2014  E60.00 MPH       MACOMB             MI   TRAINED SPOTTER

            JUST NORTH OF 11 MILE RD ON HOOVER IN WARREN.

0338 PM     TSTM WND DMG     5 W MACOMB TOWNSHIP     42.67N 83.01W
05/13/2014                   MACOMB             MI   PUBLIC        

            TWO LARGE TREES DOWN AT 23 MILE AND SHELBY. REPORT VIA
            FACEBOOK.

0338 PM     TSTM WND DMG     MELVIN                  43.18N 82.86W
05/13/2014                   SANILAC            MI   911 CALL CENTER

            POWER POLE AND WIRES DOWN. TIME ESTIMATED FROM RADAR.

0355 PM     MARINE TSTM WIND MOUNT CLEMENS           42.60N 82.88W
05/13/2014  M39.00 MPH       MACOMB             MI   ASOS          

0400 PM     TSTM WND DMG     COLUMBUS                42.89N 82.67W
05/13/2014                   ST. CLAIR          MI   BROADCAST MEDIA

            LARGE TREE DOWN ON TRUCK.

0415 PM     TSTM WND DMG     5 ENE RICHMOND          42.83N 82.67W
05/13/2014                   ST. CLAIR          MI   911 CALL CENTER

            TREES DOWN/POWER OUT GRATIOT AND ELLSWORTH.

0417 PM     MARINE TSTM WIND PORT HURON              42.99N 82.43W
05/13/2014  M40.00 MPH       ST. CLAIR          MI   TRAINED SPOTTER

0421 PM     TSTM WND DMG     SSE ST. CLAIR           42.82N 82.49W
05/13/2014                   ST. CLAIR          MI   911 CALL CENTER

            MULTIPLE REPORTS OF TREES AND POWER LINES DOWN

0440 PM     FLOOD            6 NNW GROSSE POINTE     42.47N 82.94W
05/13/2014                   MACOMB             MI   TRAINED SPOTTER

            WATER OVER ROADS BETWEEN GRATOIT AND KELLY STREETS.

0453 PM     TSTM WND DMG     4 E RICHMOND            42.81N 82.68W
05/13/2014                   ST. CLAIR          MI   911 CALL CENTER

            TREES DOWN/POWER OUT. BARTEL RD.

0453 PM     TSTM WND DMG     SSE ST. CLAIR           42.82N 82.49W
05/13/2014                   ST. CLAIR          MI   911 CALL CENTER

            TREES DOWN/POWER OUT HATHAWAY/OAKLAND RD.
___________________________________________________________________
Rest of the week's Outlook...

Update 5/14/14; First More Rain Then the Cold as Previously Noted

Low pressure system along the cold front that pushed the cold front and severe weather through here Tuesday; has moved northeast well into Canada. However with a strong nearly parallel jet aloft along with upper level energy and copious amount of moisture, look for rain and a few embedded thunderstorms to make an appearance overnight into Thursday. Rainfall amounts of  around .50" to 1.50" will be widespread with locally higher amounts.

After our mid week rain; the much cooler air mentioned days ago in this current blog will mover into the area Thursday night through the weekend. While temperatures will drop into the mid 30s to lower 40s on the coldest early mornings (most likely Friday and Saturday morning); the highest risk of frost will be in open areas where the ground has dried out some. With the strong warm up recently and heavy rains; those factors will tend to negate frost development due to surface and below ground temperature moderation. In addition as always, cloud cover and wind will also help dictate outcome.

Still one can not rule it (patchy frost) out as the air coming across the region is notably cold for mid May. Perusing records for mid May is a help at determining what have been the worst cold snaps so late in spring. As you can see record cold lows around 30 degrees have been the lowest, while very cool afternoon highs have been in the mid to upper 40s for record low max's. I feel most of these will remain intact.

Detroit Rec       Hi's     Low Max's        Rec Low's
16 70 49 60.0 92/1962 47/1945 70/1962 32/1984 81/1962 44/1957 1.09/1945 16
17 70 50 60.0 93/1962 48/1916 67/1962 31/1973 80/1962 43/1973 1.22/1980 17
18 71 50 60.0 93/1962 48/1915 70/1962 32/1973

Flint Rec           Hi's     Low Max's         Rec Low's
16 69 45 57.0 90/1962 46/1945 65/1962 30/1921 78/1962 41/1956 2.16/1974 16
17 69 46 57.0 89/1962 47/2002 62/1999 29/1973 75/1999 41/2002 1.85/1923 17
18 69 46 58.0 90/1998 48/2002 64/1962 29/1973

Saginaw Rec    Hi's     Low Max's         Rec Low's
16 68 47 57.0 90/1962 46/1923 67/1962 32/1952 79/1962 42/1983 1.40/1923 16
17 68 47 58.0 89/1936 45/1916 63/1977 32/1983 75/1977 41/2002 1.98/1986 17
18 69 47 58.0 92/1998 49/1969 64/1971 31/1925

_______________________________________________________________



Update...5/11/14

Sunday afternoon's Severe Weather Update for Monday
 


May 11, 2014 1730 UTC Day 2 Convective Outlook
Updated: Sun May 11 17:30:53 UTC 2014 (Print Version | 20140511 1730Z Day 2 shapefile | 20140511 1730Z Day 2 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Probabilistic
 Population  Cities  CWAs  Interstates  Counties  ARTCC  FEMA Regions
 
Categorical Day2 1730Z Outlook
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 228,089 32,443,953 Chicago, IL...San Antonio, TX...Austin, TX...Milwaukee, WI...Kansas City, MO...
 Forecast Discussion
   SPC AC 111729

   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1229 PM CDT SUN MAY 11 2014

   VALID 121200Z - 131200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER MO
   VALLEY...MID TO UPPER MS VALLEY AND SRN GREAT LAKES REGION...

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SW AND CNTRL
   TX...

   ...SUMMARY...
   CLUSTERS OF SEVERE STORMS ARE POSSIBLE FROM THE SOUTHERN GREAT LAKES
   SOUTHWESTWARD INTO THE MID TO UPPER MISSISSIPPI VALLEY MONDAY
   AFTERNOON AND EVENING.  SEVERE THUNDERSTORMS WILL ALSO BE POSSIBLE
   IN THE SOUTHERN GREAT PLAINS MONDAY AFTERNOON AND EVENING. DAMAGING
   WINDS AND LARGE HAIL SHOULD BE THE PRIMARY HAZARDS ALTHOUGH AN
   ISOLATED TORNADO THREAT CAN NOT BE RULED OUT.

   ...MID TO UPPER MS VALLEY/GREAT LAKES...
   AN UPPER-LEVEL TROUGH WILL MOVE INTO THE CNTRL AND NRN PLAINS ON
   MONDAY AS A COLD FRONT ADVANCES SEWD ACROSS THE MID MO VALLEY AND
   CNTRL PLAINS. AT THE START OF THE PERIOD...SCATTERED THUNDERSTORMS
   APPEAR LIKELY TO BE ONGOING NEAR THE EXIT REGION OF THE LOW-LEVEL
   JET IN PARTS OF THE UPPER MS VALLEY AND MID MO VALLEY. THIS ACTIVITY
   SHOULD MOVE EWD DURING THE DAY AS MODERATE INSTABILITY DEVELOPS
   AHEAD OF THE FRONT FROM IA SWD ACROSS MO. THUNDERSTORMS SHOULD
   INITIATE ALONG THIS CORRIDOR DURING THE AFTERNOON ALONG AND JUST
   AHEAD OF THE BOUNDARY. OTHER STORMS MAY INITIATE ACROSS THE WARM
   SECTOR NEWD ACROSS LOWER OH VALLEY INTO THE GREAT LAKES REGION.

   NAM FORECAST SOUNDINGS AT 00Z/TUE FROM CHICAGO IL SWWD INTO CNTRL MO
   SHOW MLCAPE AROUND 1200 J/KG WITH 30 TO 35 KT OF 0-6 KM SHEAR. THIS
   SHOULD BE ENOUGH FOR STORM ORGANIZATION AS CELLS INCREASE IN
   COVERAGE LATE MONDAY AFTERNOON. STEEP LOW-LEVEL LAPSE RATES AND
   UNIDIRECTIONAL WIND PROFILES SHOULD BE FAVORABLE FOR STRONG WIND
   GUSTS WITH SHORT-LINE SEGMENTS AND MULTICELL CLUSTERS. ISOLATED
   LARGE HAIL MAY ALSO OCCUR IN AREAS THAT DESTABILIZE THE MOST.

   FURTHER TO THE NORTHEAST...MODEL FORECASTS DEVELOP A POCKET OF
   ENHANCED INSTABILITY ACROSS LOWER MI BENEATH AN EWD MOVING
   UPPER-LEVEL RIDGE. IN RESPONSE...THUNDERSTORMS MAY INITIATE ON THE
   NRN END OF THE STRONGER INSTABILITY AS LOW-LEVEL CONVERGENCE BECOMES
   ENHANCED MONDAY AFTERNOON. FORECAST SOUNDINGS AT DETROIT AT 21Z/MON
   SHOW MLCAPE AROUND 1200 J/KG WITH 35 KT OF 0-6 KM SHEAR. IN
   ADDITION...LOW-LEVEL LAPSE RATES ARE STEEP AND THERE IS SOME
   DIRECTIONAL SHEAR BELOW 850 MB. THIS SHOULD BE ENOUGH FOR AN
   ISOLATED SEVERE THREAT WITH WIND DAMAGE AND HAIL POSSIBLE.

Mid Week Notes Update:
NAM/Euro agree on bringing second low Pressure storm mid week on tail end of polar front; see if GFS comes arnd to this scenario with time. It would be very WET & psbly stormy again if that happened...depends how far north she pushes back up.




5/10/14__________________________________________________________
Model Guidance for the past few days has been coming together for the definite risk of severe weather early in the week; then a return to below to well below normal temperatures with another shot of polar air later in the week.

A developing low pressure system will surge warm, humid air back into the region on Monday and then; push a cold front through Southeast Lower Michigan later Tuesday.  Severe weather will likely form along and behind the warm front as the air becomes very unstable, especially if intensified by surface heating during the day. Another round of severe weather is possible Tuesday along and ahead of the cold front.

Latest trajectories of both the NAM and GFS models reflect strong instability building during the day Monday across Southern Lower Michigan, especially just west of the region. With CAPES projected of 2800j/k + and LI's in excess of -8 the dynamite will be set. Even assuming these parameters are a bit overdone, this situation needs to be watched.  Triggers for convection will be the warm and cold fronts with the system both Monday and Tuesday. While bulk shear will not be terribly strong Monday, the projected
instability may dominate decent storm development Monday; while Tuesday the jet core and bulk shear will be on our doorstep to add to the threat but it's too early for certainties.

As of now, SPC has much of Southern Lower Michigan outlooked for a slight chance of severe weather Monday into Tuesday. I wouldn't be surprised if they increased the slight risk over parts of the outlooked area to moderate,especially if the atmosphere continues to be modeled and projected this way. Keep abreast of potential severe weather information into early next week.






Monday AM - Tue AM Outlook
Updated: Sat May 10 07:22:52 UTC 2014 (Print Version | 20140510 0730Z Day 3 shapefile | 20140510 0730Z Day 3 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Probabilistic
 Population  Cities  CWAs  Interstates  Counties  ARTCC  FEMA Regions
 
Categorical Day3 0730Z Outlook
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 268,098 38,197,072 Chicago, IL...Dallas, TX...Ft. Worth, TX...Milwaukee, WI...Kansas City, MO...
 Forecast Discussion
   SPC AC 100720

   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0220 AM CDT SAT MAY 10 2014

   VALID 121200Z - 131200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL GREAT LAKES TO
   THE SRN PLAINS...

   ...SUMMARY...
   ISOLATED SEVERE STORMS ARE POSSIBLE FROM THE CENTRAL GREAT LAKES TO
   THE SOUTHERN GREAT PLAINS THROUGH MONDAY EVENING.

   ...SYNOPSIS...
   A SRN-STREAM SPEED MAX EJECTING OUT OF THE BASE OF AN AMPLIFIED
   UPPER-LEVEL TROUGH LATE D2 SHOULD PROGRESS ACROSS THE CNTRL PLAINS
   INTO THE UPPER MS VALLEY BY EARLY TUE. ATTENDANT SURFACE CYCLONE
   ALONG A MERIDIONAL COLD FRONT SHOULD TRACK ACROSS THE UPPER MS
   VALLEY TO NEAR LK SUPERIOR. TRAILING PORTION OF THE FRONT WILL PUSH
   E/SEWD ACROSS THE MID-MS VALLEY AND SRN PLAINS...WITH DIFFERENCES IN
   BOUNDARY PLACEMENT AMONG GUIDANCE MOST PRONOUNCED DURING THE FIRST
   HALF OF THE PERIOD.

   ...CENTRAL GREAT LAKES TO SRN PLAINS...
   SCATTERED TO WIDESPREAD CONVECTION IS ANTICIPATED TO BE ONGOING AT
   12Z/MON ALONG BOTH THE COLD FRONT OVER THE GREAT PLAINS AND
   DOWNSTREAM WAA REGIME OVER THE GREAT LAKES. WITH A RESIDUAL EML
   PLUME LIKELY ACROSS UNDISTURBED PORTIONS OF THE WARM
   SECTOR...DIURNAL HEATING SHOULD SUPPORT AT LEAST MODERATE BUOYANCY
   DEVELOPING AHEAD OF THIS ACTIVITY FROM THE OZARK PLATEAU TO S TX.
   HOWEVER...WIND PROFILES WITH SRN EXTENT WILL BE WEAKER AND PROBABLY
   CHARACTERIZED BY VEER-BACK SIGNATURES IN THE MID-LEVELS...GIVEN THE
   TRACK OF THE PLAINS SHORTWAVE IMPULSE. ALTHOUGH STORM CLUSTERS WILL
   LIKELY INCREASE IN COVERAGE DURING THE DAY...SMALL HODOGRAPHS
   SUGGEST CONVECTION WOULD STRUGGLE TO ORGANIZE AND GENERALLY REMAIN
   ON THE MARGINS FOR BOUTS OF SEVERE WIND/HAIL.

   FARTHER N FROM THE MID-MS VALLEY TO CNTRL GREAT LAKES...WIND
   PROFILES WILL BE MORE CONDUCIVE TO ROTATING UPDRAFTS.
   HOWEVER...EXTENSIVE ONGOING CONVECTION WILL PROBABLY HAVE
   DELETERIOUS EFFECTS ON INSTABILITY...ESPECIALLY WITH ANY POTENTIAL
   REDEVELOPMENT ALONG THE FRONT DURING PEAK HEATING. FOR NOW...WILL
   BROAD-BRUSH WITH LOW-END SLIGHT RISK PROBABILITIES.

   ..GRAMS.. 05/10/2014
 
 
After the severe weather threat leaves; another "bowling ball" mega cold vortex is 
projected by most models to move over the region late in the week. This is expected 
to bring below to well below normal temperatures late in the week. Look for more on
the particulars of that event, in a few days. Timing of the colder weather along with 
actual temperatures will become more apparent by early-mid week. Gardeners
and Nurserys; stay tuned. 

Making weather fun while we all learn, 
Bill Deedler -SEMI_WeatherHistorian