Area forecast discussion
National Weather Service Detroit/Pontiac Michigan
601 am EDT Thursday Jun 20 2013
Aviation...
//discussion...
High pressure centered over Lake Huron will maintain control across
the region through tonight. Mainly clear skies and light south to
southeast winds during this time.
//Dtw threshold threats...
* none
&&
Previous discussion...issued 328 am EDT Thursday Jun 20 2013
Short term...today and tonight
1022 mb surface high situated beneath slightly confluent middle level
northwest flow will ease eastward with time through tonight...
tending to anchor over Lake Huron. This will continue to provide
plenty of clear sky and dry conditions. This process will yield a
slight upward adjustment in the height field while veering the low
level gradient gradually toward a south/southeast component by
afternoon. Under full June insolation...this will translate into a
4-5 degree warming trend off readings noted on Wednesday. Highs look
to arrive within the upper 70s/near 80 range.
Lows tonight will also see a corresponding move upward within this
moderating airmass. Readings largely in the 55 to 60 degree
range. Weak middle level trough currently exiting the Dakotas will
arrive during the early morning period. Slight increase in ascent
along this feature may be enough to generate some high level
cloud...but sufficient depth to the dry layer beneath will keep
precipitation chances none.
Long term...Friday through Wednesday
Forecast reasoning for the next several days is unchanged. Despite a
high confidence evolution to the large scale pattern, local weather will
be strongly modulated by local & upstream convective trends which
impairs predictability beyond day 2.
Middle-level westerlies are forecast to emerge across the northern tier
of the United States by the end of the week as impulses embedded
within the large Pacific northwest low trigger multiple organized convective
episodes across the northern plains/upper Midwest. This will allow a
warm and humid airmass to spill eastward into the Great Lakes region
yielding upper-end high temperature potential in the 90s for most of
the long term. However, as is typical during the warm season, daily
convective trends will play the first order role in determining
actual observed temperatures. Therefore, moved forward in similar
fashion to the inherited forecast which depicts slightly warmer than
average temperatures hovering in the upper 80s. Support for such an
approach is offered by numerous consecutive runs of the ECMWF, which
has maintained that Southeast Michigan will remain favorably
positioned along the edge of the middle-level cap for the next several
days. This will put the County Warning Area in line to see both direct & indirect
effects of multiple convective episodes and justifies a conservative
methodology. Still see no reason to contend with European model (ecmwf) depiction of
an MCS, or remnants thereof, impacting the area on Saturday.
Although severe potential cannot yet be defined, probable early-day
timing does suggest diminished severe potential.
A growing Reservoir of instability will become established
Sunday-Wednesday as a robust zonally-oriented eml ribbon is carried
into the Great Lakes by emerging westerly flow. Per the usual, this
will make convective potential increasingly dependent upon the
ability of available forcing to overcome Stout middle-level capping.
Marine...
Favorable marine conditions will exist today and tonight as high
pressure remains anchored over the region. A warmer and more
unstable environment will gradually work into the region heading
into next weekend. This will bring the next chance of showers and
thunderstorms.
&&
DTX watches/warnings/advisories...
Michigan...none.
Lake Huron...none.
Lake St Clair...none.
Michigan waters of Lake Erie...none.
&&
$$
Aviation.....Mr
short term...mr
long term....jvc
marine.......mr
You can obtain your latest National Weather Service forecasts online
at www.Weather.Gov/Detroit (all lower case).
