253
FXUS63 KAPX 150113
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
913 PM EDT Sat Sep 14 2024

.KEY MESSAGES...

- Rain-free weather and warm (possibly record breaking?)
  temperatures likely to increase fire weather and near term
  drought concerns.

&&

.UPDATE...
Issued at 913 PM EDT Sat Sep 14 2024

Another quiet...clear and calm night across our Northwoods
thanks to persistent high pressure and dry air thru the column,
Little will change overnight...other than some patchy fog
development again. Overnight lows will cool into the 50s.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 325 PM EDT Sat Sep 14 2024

Pattern Synopsis: Persistent upper-level trof west/ridge east
configuration in place across North America. Short wave energy
coming out the the northern Plains/Canadian Prairies will flatten
the ridge somewhat heading into Sunday. However, additional energy
diving down the Pacific coast will reload the trof and help the
pattern amplify overall heading into next week.

Forecast Details: Given the stagnant pattern that has been in place
and will remain through the period, a slightly modified persistence
forecast is likely to do well. In other words... continued dry and
mild. The short wave energy topping the ridge overhead heading into
tomorrow will lower heights a touch for Sunday. This combined with a
little more associated cirrus should result in temperatures a few
degrees cooler than current forecast for Sunday highs...likely close
to what we are seeing today. Before we get to Sunday, another
comfortable night with lows mainly in the 50s is anticipated. The
patchy fog of the past couple night is likely to make an appearance
once again given the good radiational cooling setup.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 325 PM EDT Sat Sep 14 2024

Pattern Forecast: North American pattern to start this weekend
features a closed 500mb high centered over the Great Lakes/southern
Ontario (+1 to +2 sigma height anomaly/590dam 500mb height off the
12z APX sounding which looks like it ties the record for this
observation time).  Broad mean troughing over western Canada/
northwest quadrant of the CONUS extending back into the northeast
Pacific. Upper level remnants of what was TC "Francine" drifting
over the lower Mississippi Valley. 588+dam 500mb high will remain
over the Great Lakes to start next week while elongating across New
England...while troughing amplifies along the west coast and
eventually leads to a closed low developing over California Monday.
Upper ridge weakens by Tuesday though the Great Lakes will remain
under weak flow aloft as troughing remains over the west coast as a
second upper low develops over California in sort of a discontinuous
retrogression fashion. This basic trough west/ridge east idea
expected to continue into the latter half of the week. One area to
watch will be over the southeastern U.S. where there will be
weakness in the pattern that may end up allowing a system with
tropical/subtropical characteristics to spin up along the mid
Atlantic coast early next week.  Whether this gets close enough to
Michigan to have any direct impact remains to be seen...but an
indirect impact may be to help narrow the wavelength between the
western trough and falling heights over Atlantic Canada.  This would
result in a narrow amplified ridge across the Midwest and Great
Lakes heading into next weekend.

Surface high pressure will stretch from New England back into the
Great Lakes Sunday...which doesn`t change much at all for Monday and
Tuesday...maybe Wednesday as well under the assumption that whatever
quasi-tropical system tries to develop along the mid Atlantic will
not be an issue this far north.  A deep layer dry anticyclonic
trajectory into Michigan for this coming week...and with that will
come an extended period of above normal temperatures.

Primary Forecast Concerns:

Rain-free weather and warm temperatures likely to increase fire
weather and near term drought concerns: A couple more dry/sunny days
in store Monday and Tuesday...will be interesting to see how much
boundary layer feedback we get as soils continue to dry out (more
sensible heat flux/less latent heat flux....perhaps "overachieving"
temperatures with a little deeper BL and dew points that mix out a
bit more).  Regardless looking at highs into the 80s for Monday and
Tuesday...possibility of more cloud cover getting thrown back across
Lower Michigan Wednesday may knock temperatures down a few degrees.
But getting to the time of year where there are more record highs in
the 80s than 90s: Records for Monday/Tuesday are GLR 88/86...ANJ
85/88...HTL 88/89...TVC 90/90...APN 90/92...PLN 89/87.  So will be
close to some records for certain.  Recent dryness is also becoming
a concern...14 day precipitation departures are less than 10 percent
of normal and the D0 (Abnormally Dry) drought category now across
eastern Upper and along/west of US-131 in northern Lower.  Fire
danger ratings also in the high-very high category across northern
Lower...with no improvement in the near term.  Fortunately not a lot
of wind expected through early next week but can see minimum
relative humidity values dropping below 30 percent across the
interior both Monday and Tuesday.  Probably worth mentioning
elevated fire danger in the Hazardous Weather Outlook through at
least Tuesday especially given the burn bans in place across all of
northern Lower.

As of now (given caveats with developments over the mid Atlantic)...
no precipitation probabilities in the forecast through next week
with above normal high temperatures for each day during the latter
half of the week as well.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 700 PM EDT Sat Sep 14 2024

Strong ridging/subsidence/dry will maintain control thru Sunday
night. Aside from some patchy fog/IFR vsbys overnight...VFR
conditions will remain the rule for the next 24 hours. Light SE
winds tonight will strengthen AOB 10 kts on Sunday.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

UPDATE...MLR
SHORT TERM...PBB
LONG TERM...JPB
AVIATION...MLR