Blog Post: http://www.weatherspotlight.com/?p=397
Update 1: Added radar image covering High Risk area for today.
Update 2: Added Chat Room Link
LIVE CHAT for TONIGHT
Radar Notes - Red line is High Risk area, Yellow line is Moderate Risk area, Green line is Slight Risk Area.
TWDR TDTW High-Res Radar
IWX Level 3 Radar
SPC Day 1 Outlook - 1630Z Update
Previous Discussions below
Wednesday June 12th could be a fairly active day across the Lower Great Lakes region as warm unstable air will be pushing up from the south. Currently models arenít in all that great of agreement on what will take place, mainly having issues on frontal placement, but it appears a risk of damaging winds and hail will be possible. The tornado threat right now looks low as there are some limiting factors that should keep a more widespread threat mitigated.
12Z NAM Discussion
By late afternoon/early evening a warm front should extend from Northern IL through Southern MI. North of the front will be relatively cool temps in the 60s and 70s, whereas south of the front weíll see temps in the 80s to near 90 in spots. Instability will be fairly high with CAPE values in the 3000-4000 j/kg range. Moisture will be well represented with dewpoints into the upper 60s and low 70s over much of the area.
Forecast soundings show winds will exhibit some areas of speed shear back over IL and then big to develop some directional shear into IN and OH. However, most of the winds will have a westerly component to them and this would aid in more of a fast moving west to east cluster of storms. Moving into the evening, especially over E IN and OH, winds will start to back from the S to SE as a surface low moves up the approaching cold front (from the NW) which could allow storms to being to take on more classic supercell characteristics and rotate. It isnít locked in yet, but it is still worth noting.
KTOL Forecast Sounding @ 11PM Wednesday
NAM Forecast Map with Outlined Risk Area
12Z GFS Discussion
The GFS is holding the warm front a bit further south into Northern IN/OH, but still has similar features such as the NE moving surface low along the approaching cold front. The GFS keeps the storm complex near this surface low moving it up through much of IL, IN and OH. Timing is also a bit slower than NAM, which highlights IL for afternoon/evening, IN for Evening, and MI/OH for overnight into Thursday.
Not much to really add here as they arenít all that different except for placement. Hopefully through the runs later today weíll see them come closer together in agreement on the exact placement of the boundaries. Right now the main threats would be widespread damaging winds, some hail, and a couple tornadoes here are there.
SPC does have a 15% slight risk out for much of this area, more than I highlighted above. They do are discussing the uncertainty surrounding the current models.
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0230 AM CDT MON JUN 10 2013
VALID 121200Z - 131200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MIDWEST U.S....
AN UPPER TROUGH CENTERED OVER THE PAC NW IS FORECAST TO MAKE SLOW
EWD PROGRESS DAY 3...WHILE TROUGHING ALSO PERSISTS OVER ERN CANADA
AND INTO NEW ENGLAND. BETWEEN THESE TWO FEATURES...BROAD RIDGING
WILL PREVAIL ACROSS MUCH OF THE CONUS. WITHIN THE RIDGE HOWEVER...A
FAIRLY STRONG SHORT-WAVE TROUGH IS FORECAST TO TRAVERSE THE
MIDWEST/OH VALLEY REGION THROUGH THE PERIOD.
AT THE SURFACE...A COLD FRONT IS FORECAST TO MAKE EWD PROGRESS
ACROSS THE NWRN PORTION OF THE COUNTRY IN CONJUNCTION WITH THE
ADVANCING UPPER TROUGH...AND A LOW/FRONTAL SYSTEM WILL LIKEWISE
SHIFT ACROSS THE MIDWEST IN TANDEM WITH THE MIDWESTERN UPPER SYSTEM.
AS THE POTENT SHORT-WAVE TROUGH CROSSES THE MIDWEST...EXPECT SHOWERS
AND THUNDERSTORMS TO INCREASE THROUGH THE AFTERNOON...WITHIN AN
AIRMASS ACQUIRING MODERATE INSTABILITY IN CONJUNCTION WITH DAYTIME
HEATING. THE GFS AND NAM DIFFER WITH SURFACE FRONTAL EVOLUTION/LOW
POSITION ACROSS THIS AREA...SO DETAILS REMAIN DIFFICULT TO
DETERMINE...BUT IN GENERAL A RELATIVELY BROAD ZONE OF AT LEAST
ISOLATED HAIL/WIND POTENTIAL IS EVIDENT GIVEN MODERATE WLY WINDS
WITHIN THE LOWER TO MIDDLE TROPOSPHERE ACROSS THIS REGION. ONCE
DETAILS BECOME A BIT MORE CLEAR...MORE SUBSTANTIAL WIND THREAT MAY
BECOME EVIDENT ACROSS PARTS OF THIS AREA...WHICH WOULD WARRANT
INCREASED PROBABILITIES IN LATER FORECASTS.