fxus63 kdtx 191744
area forecast discussion
national weather service detroit/pontiac mi
1244 pm est wed feb 19 2020
increasing upper level confluence over the mid-upper mississippi
river valley is leading to strong surface ridge expansion into lower
michigan today. the surface ridging will only expand throughout the
taf period. notable signal for surface boundary layer mixing and
surface winds have mixed down to 12 knots or less for all areas.
maturation of pbl after 20z will result in few boundary layer
cumulus with better lake moisture confined to areas generally north
of the forecast area. the canopy of stratocumulus will likely expand
southward and my impact kmbs,kfnt with broken cigs for a time this
evening. shortwave energy passing eastward may interact with a
baroclinic zone and result in high cloud tonight. issue with this is
that the front is forecasted to be largely frontolytic. winds
tonight will remain light 5 knots or less, west or northwesterly as
surface based inversion develops.
dtw threshold probabilities...
* low for ceiling 5000 ft or late afternoon/evening.
issued at 336 am est wed feb 19 2020
quiet weather expected today through saturday as a strong and
expansive arctic high pressure system takes hold of the region. it
will be centered over the northern plains this morning and then will
slowly drift southeastward through the end of the week eventually
reaching tn/ky by friday.
an arctic front pushed south through lower mi overnight helping to
pull some moisture off the western lakes through southern mi. an
isolated ob or two showed some snow but generally speaking it
resulted in enhanced cloud cover. the front did mark the beginning
of a mid week cool down as a positively tilted thermal trough
settles over the state. 850mb will drop into the negative teens
today, down from the 0c to -5c we had on tuesday. highs today will
be limited to the upper 20s for most locations. there is an outside
shot at some flurries this afternoon as cold northwest flow sparks
some lake enhanced clouds, and possibly snow showers over the west
part of the state. the thinking is that the high is already becoming
well established over the area with surface pressure around 1028mb
and a strong subsidence inversion around 3kft. this shallow boundary
layer doesn`t allow for much moisture to work all the way east into
the area through the dry airmass, especially considering
northwesterly flow making a longer trek for the moisture. will keep
the forecast dry at this point and allow the day shift to add
flurries where necessary if satellite signature warrants it.
a second arctic front will sweep down through the region late
tonight into thursday. the core of the cold air, near -20c, will
glance the region allowing for temps to bottom out around 10f
tonight. there will again be an outside chance of some flurries as
the flow backs a bit more westerly along the front but may also just
be more of a virga scenario as a pocket of mid level moisture passes
overhead seeding the drier air below. temps will remain in the 20s
once again with the thermal trough still overhead.
as the high drifts more to our south on friday, surface flow will
become more southwesterly. this while the mid level ridge folds over
into the region resulting in westerly flow aloft. both will result in
a warming airmass boosting high temps back into the mid 30s. the
pattern will hold through saturday allowing further moderation to
the airmass with highs increasing into the 40s for both saturday and
sunday. the next chance of precipitation won`t come until sunday
night as a southern stream storm is forecast to pass to our south
while the northern periphery of the precip shield lifts into
high pressure over north dakota will expand southeastward bringing
dry conditions and low-impact waves today. cold northwest flow
behind a passing arctic front will maintain a few more hours of
freezing spray near the central lake huron international border with
a few lingering light snow showers. winds will fluctuate between
westerly and northwesterly in the 10-15 knot range over the next few
days. air temperatures remain chilly through the remainder of the
work week as the arctic airmass remains positioned over the great
lakes. by friday afternoon, the high will reach the mid mississippi
valley causing local flow to back to the southwest, transitioning
the region to a warm advection regime. a stronger gradient will
develop as a low pivots through hudson bay, generating strong winds
friday afternoon/evening with favorable 850 mb llj dyanmics allowing
for 30-35 knot surface gusts during the evening/overnight period.
lake st clair...none.
michigan waters of lake erie...none.
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