Area forecast discussion
National Weather Service Duluth Minnesota
120 PM CDT Sat may 25 2013
Aviation.../18z taf issuance/
widespread VFR conditions will persist throughout the taf cycle as
high pressure to the east battles low pressure to the west. There
could be some scattered lower clouds but all in all it looks like
like VFR conditions with mainly high to middle clouds.
&&
Previous discussion... /issued 1039 am CDT Sat may 25 2013/
Update...shaved probability of precipitation lower and farther west for remainder of
morning per latest trends on 88d/surface observation. Lowered sky coverage as
building middle level ridge should allow thinning of middle cloud canopy
and this appears to be the case on animation of visible imagery past
few hours. Lifted maximum temperatures 1 to 3 degrees but may need additional
upwards adjustment.
Previous discussion... /issued 633 am CDT Sat may 25 2013/
Aviation...12z taf issuance...
VFR conditions with vcsh through this morning. Light southeast winds
this morning increasing during the afternoon to 10-15 knots. Could
see scattered middle clouds this afternoon...and scattered low clouds late
tonight/early Sun morning.
Previous discussion... /issued 327 am CDT Sat may 25 2013/
Short term...today through Sunday...
axis of weak warm advection and frontogenesis maxed out in the
700-600mb layer continues to translate slowly eastward across
eastern Minnesota early this morning while slowly weakening. Northwest-southeast
oriented band of showers has slowly diminished in both coverage
and intensity over the past couple of hours..and should continue
to do so through middle morning today. However..until low-middle level
flow backs as it starts to feel the influence of the next wave
moving from The Rockies into the northern plains there will be at least
some modest forcing for ascent..and a few showers could persist
into late morning.
By this afternoon..main threat for additional showers/thunderstorms is
expected to consolidate to areas mostly south and west of the
Duluth County Warning Area in closer proximity to low level baroclinic zone from
the Dakotas into the middle Missouri Valley. As a result..we have
continued the previous trend of a dry forecast for this afternoon
in most areas as east/southeast low level flow brings a flux of
drier air into the region. The far southwest County Warning Area will remain close
enough to the low level thermal/moisture gradient to warrant at
least a mention of a few showers tonight. Chances for showers then
expand a bit farther eastward on Sunday as next wave brushes
northeastward..along with some contribution from enhanced
warm/moist advection by the low level jet late Sat night and Sunday morning.
Easterly boundary layer flow will also keep areas near Lake
Superior cooler today and Sunday..along with locally gusty winds
in some of the favored locations near the twin ports and Ashland.
Long term...Sunday night through Friday night...
a period of active weather will develop this week with multiple
disturbances moving across the upper Midwest...producing rain
showers and thunderstorms Monday through Saturday. Upper level
ridge axis across the region late this weekend will shift eastward on
Monday as a 500mb short wave pushes into the ridge across the northern plains
on the leading edge of a long wave trough over the western Continental U.S.. this
short wave is expected to have an associated surface inverted trough/warm
front lift northward through central Minnesota on Monday. Rain shower chances
will increase during the day Monday...along with a slight chance of
T-storms. A low level jet will develop Monday night/Tuesday morning and usher in a
moist unstable air mass across the region. The interaction of this
short wave and increased instability/moisture will allow for the
potential of MDT/heavy rain showers and even a few strong storms
through Tuesday morning. The active pattern continues through the
middle and latter part of the week as the long wave trough over
the west transitions eastward and continues to draw up a robust
amount of warm moist air from the south and produces rain showers and
scattered T-storms across the Northland into the early part of the
weekend. There are notable differences in the synoptic patterns of
the European model (ecmwf) and GFS during this week...which lead to unresolvable
convective modes. At this time...will continue with high chance
probability of precipitation...low likely probability of precipitation. It will be difficult to nail down specific
times/locations of the best/heaviest precipitation and any T-storm
chances until well into the week.
Temperatures will continue on the warming trend through the week
with highs on Monday in the 60s...and overnight lows in the 40s. By
Wednesday...highs will be topping out in the 70s and lower
80s...with night time lows in the 50s and 60s.
&&
Point temps/pops...
dlh 59 41 62 45 / 20 10 10 10
inl 64 43 69 47 / 40 10 0 20
brd 61 45 63 50 / 40 10 20 40
hyr 64 41 69 47 / 20 10 10 20
asx 61 39 63 43 / 10 0 0 0
&&
Dlh watches/warnings/advisories...
Minnesota...none.
WI...none.
Ls...none.
&&
$$
Short term...Cannon
long term....dap
aviation...dap
