Post by MugRB on Apr 23, 2011 23:01:09 GMT -5
Synopsis...(3:30 PM EDT Sat Apr 23 2011)
high pressure will settle in for tonight providing the region with
relatively dry weather through Sunday. However warm front will lift
northward into Michigan by Tuesday leading to unsettled weather.
This wet weather pattern will persist into Thursday...but then
another area of high pressure will move in for Friday.
Short term...(330 PM EDT Sat Apr 23 2011)
(tonight through Monday night)
Mainly dry for tonight through Sunday afternoon with high pressure
in control. Areas around Kalamazoo and Jackson could see a light
rain shower during this timeframe as a weak middle level wave clips
that region. There were a few sprinkles upstream over in Kansas
associated with this feature.
A much better shot for rain arrives Sunday night and Monday as a
weakening wave of low pressure moves in from the southwest. This
feature stays south of Kalamazoo. The nose of the low level jet
arrives around 12z Monday for Kalamazoo to Jackson based off of the GFS
model...but the NAM is further south. The GFS as a result is much
wetter...while the NAM is almost dry. The new high res Euro is in
between the two and does support rain for Southern Lower Michigan. This
system Sunday night into Monday will add to the already wet
conditions...but it should depart off to the east during the
afternoon.
By 12z Tuesday though a more widespread area of showers and
thunderstorms will hit the area as a strong upper trough pulls in
from the southwest. Areas of heavy rain may occur given the very
high precipitable water airmass that it will have to work with and
the low level jet pulling through.
Could be some patchy fog around daybreak Sunday given the weakening
winds and moist soil conditions.
Long term...(330 PM EDT Sat Apr 23 2011)
(tuesday through saturday)
we/ll be following the European model (ecmwf)/NAM as the GFS appears a bit too quick
in moving the storms through the Great Lakes. However that won't
make too much of a difference in the forecast. It still looks wet.
The GFS continues to be a bit more progressive than the European model (ecmwf) and
NAM. As a result...the GFS moves a low across the County Warning Area Tuesday while
the other models are a little slower and farther west. With the western
solution the low is forecasted to move across northern Illinois/southern Wisconsin
Tuesday. That will place the County Warning Area in the more unstable warm sector.
Went with likely probability of precipitation for thunderstorm but think the heavy rain threat may be
mitigated by precipitable water values less than an inch Tuesday.
That said rain will be a factor through Thursday. After the Tuesday
storm moves northeast two more will follow. One Wednesday and one
Thursday. Each low will bring some rain with it. Instability remains
highest well south of the County Warning Area so a severe threat doesn/T look all that
great except perhaps on Tuesday when shear values briefly touch 50
kts. Friday looks like the best chance for dry weather but that will be
short lived as another frontal boundary moves north toward the County Warning Area
Friday night/Saturday.
Aviation...(810 PM EDT Sat Apr 23 2011)
as the surface winds become light tonight... there is concern about fog
formation. The current thinking is that only light/MVFR category fog
will develop since cloud cover is rather extensive... however should
considerable clearing develop then the visibility could deteriorate into
the IFR category between roughly 08z-14z. VFR conditions will return
after 14-15z after any fog mixes out.
A few light rain showers could fall along the I-94 corridor
overnight... but lower ceilings/visibilities are not expected to accompany the
showers.
Marine...(330 PM EDT Sat Apr 23 2011)
some of the Lakeshore sites from kbeh to kldm are experiencing gusts
over 23 knots...so will maintain the advisory. Winds and waves will
diminish this evening.
GRR watches/warnings/advisories...
Michigan...none.
Lm...Small Craft Advisory in effect for the entire nearshore through
this evening.
Hydrology...(330 PM EDT Sat Apr 23 2011)
little or no precipitation expected through Sunday. However several
waves of low pressure will bring a risk for heavy rain to the region
beginning Monday. Given the saturated soil and elevated
streamflows...an increased risk for flooding exists. Uncertainty
remains on the extent of the impact of any flooding as there will
be breaks in the rainfall and it is not known if the heavy rain will
fall over the same area with each event. Models have also been
rather variable with the location and timing of the heavier rain
leading up to this potential event. Still we will need to monitor
the situation closely in the coming days.
high pressure will settle in for tonight providing the region with
relatively dry weather through Sunday. However warm front will lift
northward into Michigan by Tuesday leading to unsettled weather.
This wet weather pattern will persist into Thursday...but then
another area of high pressure will move in for Friday.
Short term...(330 PM EDT Sat Apr 23 2011)
(tonight through Monday night)
Mainly dry for tonight through Sunday afternoon with high pressure
in control. Areas around Kalamazoo and Jackson could see a light
rain shower during this timeframe as a weak middle level wave clips
that region. There were a few sprinkles upstream over in Kansas
associated with this feature.
A much better shot for rain arrives Sunday night and Monday as a
weakening wave of low pressure moves in from the southwest. This
feature stays south of Kalamazoo. The nose of the low level jet
arrives around 12z Monday for Kalamazoo to Jackson based off of the GFS
model...but the NAM is further south. The GFS as a result is much
wetter...while the NAM is almost dry. The new high res Euro is in
between the two and does support rain for Southern Lower Michigan. This
system Sunday night into Monday will add to the already wet
conditions...but it should depart off to the east during the
afternoon.
By 12z Tuesday though a more widespread area of showers and
thunderstorms will hit the area as a strong upper trough pulls in
from the southwest. Areas of heavy rain may occur given the very
high precipitable water airmass that it will have to work with and
the low level jet pulling through.
Could be some patchy fog around daybreak Sunday given the weakening
winds and moist soil conditions.
Long term...(330 PM EDT Sat Apr 23 2011)
(tuesday through saturday)
we/ll be following the European model (ecmwf)/NAM as the GFS appears a bit too quick
in moving the storms through the Great Lakes. However that won't
make too much of a difference in the forecast. It still looks wet.
The GFS continues to be a bit more progressive than the European model (ecmwf) and
NAM. As a result...the GFS moves a low across the County Warning Area Tuesday while
the other models are a little slower and farther west. With the western
solution the low is forecasted to move across northern Illinois/southern Wisconsin
Tuesday. That will place the County Warning Area in the more unstable warm sector.
Went with likely probability of precipitation for thunderstorm but think the heavy rain threat may be
mitigated by precipitable water values less than an inch Tuesday.
That said rain will be a factor through Thursday. After the Tuesday
storm moves northeast two more will follow. One Wednesday and one
Thursday. Each low will bring some rain with it. Instability remains
highest well south of the County Warning Area so a severe threat doesn/T look all that
great except perhaps on Tuesday when shear values briefly touch 50
kts. Friday looks like the best chance for dry weather but that will be
short lived as another frontal boundary moves north toward the County Warning Area
Friday night/Saturday.
Aviation...(810 PM EDT Sat Apr 23 2011)
as the surface winds become light tonight... there is concern about fog
formation. The current thinking is that only light/MVFR category fog
will develop since cloud cover is rather extensive... however should
considerable clearing develop then the visibility could deteriorate into
the IFR category between roughly 08z-14z. VFR conditions will return
after 14-15z after any fog mixes out.
A few light rain showers could fall along the I-94 corridor
overnight... but lower ceilings/visibilities are not expected to accompany the
showers.
Marine...(330 PM EDT Sat Apr 23 2011)
some of the Lakeshore sites from kbeh to kldm are experiencing gusts
over 23 knots...so will maintain the advisory. Winds and waves will
diminish this evening.
GRR watches/warnings/advisories...
Michigan...none.
Lm...Small Craft Advisory in effect for the entire nearshore through
this evening.
Hydrology...(330 PM EDT Sat Apr 23 2011)
little or no precipitation expected through Sunday. However several
waves of low pressure will bring a risk for heavy rain to the region
beginning Monday. Given the saturated soil and elevated
streamflows...an increased risk for flooding exists. Uncertainty
remains on the extent of the impact of any flooding as there will
be breaks in the rainfall and it is not known if the heavy rain will
fall over the same area with each event. Models have also been
rather variable with the location and timing of the heavier rain
leading up to this potential event. Still we will need to monitor
the situation closely in the coming days.