Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Marquette Michigan
1255 am EDT Tuesday Jun 2 2015

Short term...(this evening through tuesday)
issued at 323 PM EDT Monday Jun 1 2015

Very quiet short term with frost potential the only item of concern.
High pressure over the area today has lead to clear skies and lake
breezes with maximum temperatures in the 60s inland. Southerly flow will
increase tonight into Tuesday as the high shifts east...increasing 850mb
temperatures by 3-4c. With these warmer temperatures...frost will not be as
widespread tonight...with patchy frost well inland from Lake
Superior and just inland from Lake Michigan as inland lows will be
in the low to middle 30s...but above freezing. Have issued a frost
advisory to cover this threat. The warmer airmass will also make for
warmer maximum temperatures on Tuesday...with highs in the upper 60s to middle 70s
Inland. Lake Superior breezes will not move far inland due to
stronger southerly winds.

Long term...(after midnight Tuesday night through sunday)
issued at 1153 am EDT Monday Jun 1 2015

At 00z Wednesday the upper Great Lakes will be under the 500mb
ridge...with several lows over Lake Huron...southeast Quebec...and the Tennessee
Valley. Given the proximity of all these lows expect zonal to slight
SW flow to take hold Wednesday into Thursday.

Precipitable water increase Wednesday morning...maxing out 21z Wednesday to 06z
Thursday at 1.5-1.7in. Looking at the increased instability and
daytime heating...the best chance of ts will be over the far west by
00z Thursday. This will likely remain the case through 12z Thursday
after viewing the mu cape values that only top out around 100 j/kg
over the east half overnight Wednesday night mainly thanks to the
light/more stable S flow off Lake Michigan and the fact that the surface low
over northwest Minnesota at 12z Wednesday moves into east Minnesota by 00z Thursday...but is
weakening as it GOES...pushing the surface trough west Upper Michigan by daybreak
Thursday before it flattens out.

There is some variability in the forecast solutions Thursday
night/Friday...with the Canadian solution bringing in the ridge much
faster...while the European model (ecmwf)/GFS keeps the trough in place. Will go
against the Canadian solution at this point...unless it/S 12z run
comes into better agreement. The result will be the sinking of the
expansive surface high over Hudson Bay and Ontario Thursday night to the
Great Lakes region and east Ontario/west Quebec for the start of the
weekend. The area of high pressure should exit to east on Sunday as low
pressure nears from S central Canada.

Both the GFS and European model (ecmwf) are pointing to the idea of a fairly strong
surface low over Manitoba Sunday move across Ontario and S Hudson Bay
during the day Monday /ECMWF being a farther S solution/. Look for
an increasing chance of showers Sunday over the west...albeit limited.
At this point it looks like Upper Michigan will by cut off from the best
moisture /either to the north or S/. The northwest flow will continue aloft
through at least the first half of the work week...with another
period of below normal temperatures possible.

Aviation...(for the 06z tafs through 06z Tuesday night)
issued at 1254 am EDT Tuesday Jun 2 2015

High pressure and an associated dry air mass will continue to
dominate Upper Michigan...resulting in VFR conditions through the forecast
period. Light winds will become southerly and increase this
afternoon as the high shifts toward the central and eastern lakes and low
pressure develops over the plains.

Marine...(for the 4 PM Lake Superior forecast issuance)
issued at 323 PM EDT Monday Jun 1 2015

High pressure will continue to dominate this evening...leading to light
winds mostly under 15kt. One exception will be over far Western Lake
Superior where coastal convergence and strengthening of lake breeze
circulation enhance the winds this afternoon into early evening so
that gusts reach the 20 to 25kt range locally. Winds should remain
mostly below 15kt tonight into Tuesday morning as high pressure slowly drifts
east. Heading through the middle week period...pressure gradient will not
tighten significantly between the departing high and an approaching
low pressure trough. As a result...sustained winds should be under
20kt Tuesday afternoon through early Thursday. If there are stronger winds gusting
over 20kt...they should occur over parts of the central and Eastern Lake
between the Keweenaw and Caribou Island. Passage of a low pressure
trough Thursday followed by high pressure building southeast into northern Ontario
could lead to a period of stronger NE winds later Thursday into Friday.

MQT watches/warnings/advisories...
Upper Michigan...
frost advisory until 8 am EDT /7 am CDT/ this morning for

Lake Superior...
Lake Michigan...


Short term...Titus
long term...kf

National Weather Service Glossary of Abbreviations