fxus63 kdtx 171905
area forecast discussion
national weather service detroit/pontiac mi
305 pm edt wed aug 17 2022
large upper level trough remains firmly in place across the eastern
conus keeping local conditions largely unchanged from the previous
day or two. lake breezes again are providing low level convergence
boundaries to generate scattered shower/thundershower activity early
this afternoon. while mid-level support is not as strong today as
yesterday, upper trough still allows weaker lobes of vorticity to
drop south through se mi the rest of this afternoon-evening
supporting continued popup activity- albeit at lesser coverage than
tuesday`s. capping influence is again limited today given the 12z
dtx sounding being very similar to yesterdays 12z sounding in the
mid-levels, and in fact depicts a couple degrees of cooling in the
750-650mb layer. as such have nudged up thunder mentions into chance
territory across the region for the latter half of the day. have
gotten a couple reports of pea sized hail from the stronger updrafts
however lack of shear and weaker mid-level lapse rates will prevent
anything larger than penny sized from forming. rain potential
migrates westward with the lake breezes into the interior of the cwa
over the rest of the afternoon with outflow boundaries from prior
convection providing additional focal points for initiation. any
surviving shower/storm activity begins to taper off by 00-01z with
the loss of diurnal heating (as does accompanying cloud cover)
setting up a mostly clear night allowing lows to fall into the mid to
another mid-upper level shortwave embedded in the longwave trough
drops into the northern plains thursday. in response, the persistent
upper low centered over the eastern great lakes/upstate ny shifts
further east allowing mid-level height rises tied to shortwave
ridging to build into se mi. expectation is this allows the return
of dry conditions to finish out the work week, which is supported by
most 12z solutions today. a gradual warmup accompanies the ridge as
flow veers back to the south-southwest allowing highs reaching the
mid to upper 80s by the start of the weekend. aforementioned plains
low continues to dig south leading to cyclogensis over the upper
mississippi river valley friday. this surface low tracks into the
ohio valley late saturday into sunday bringing our next chance for
widespread showers and storms.
an area of high pressure will continue to hold over eastern canada
through wednesday, bringing similar weather to what was seen on
tuesday. light northeast winds will generally hold in the 10 to 15
knot range with some gusts around 20 knots over the saginaw bay
region as the land over southern lower michigan heats up to around
80 degrees. the high pressure will weaken though the week, allowing
winds to slowly subside and become light and variable. isolated
showers will again be likely wednesday afternoon with the heating of
the day. northeasterly winds will begin to flip back to the south
overnight thursday going into friday.
issued at 112 pm edt wed aug 17 2022
isolated to widely scattered rain showers with possible thunderstorms
are expected along lake breezes/outflow boundaries this afternoon
into the evening hours. the initiating boundary will expand across
the metro terminals and into kptk initially, which is represented by
a tempo group in the tafs. low confidence that these showers will
make it into kfnt, with kmbs expected to remain dry as it holds under
a lake shadow. instability remains limited, so shower activity is
favored over thunderstorms, however, will continue to monitor
satellite and radar data for further amendments of thunderstorms.
clouds will dissipate after sunset. fog or some low stratus
development will be possible on the northern fringe of the irish
hills into the tri-cities (kfnt-kmbs), but confidence remains low
regarding fog and/or stratus coverage.
for dtw...sct-bkn 6 kft agl ceiling this afternoon with on and off
shower activity expected. an isolated thunderstorm will remain
possible with this activity.
dtw threshold probabilities...
* low for ceilings at or below 5000 ft this afternoon and early
* low for thunder from 19-01z today.
lake st clair...none.
michigan waters of lake erie...none.
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