National Weather Service Raw Text Product

Displaying AFOS PIL: AFDGRR Received: 2020-07-05 00:56 UTC


448 
FXUS63 KGRR 050056
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
856 PM EDT Sat Jul 4 2020

LATEST UPDATE...
Aviation

.SYNOPSIS...
Issued at 320 PM EDT Sat Jul 4 2020

- Hot through next week

- Next decent chance of rain Friday

&&

.DISCUSSION...(This evening through next Saturday)
Issued at 320 PM EDT Sat Jul 4 2020

-- Hot through next week --

The persistent upper ridge camped out over the Mississippi Valley 
isn't going to to move much during the next week. H8 temps in the 
16c-20c range will continue to yield highs in the lower to mid 90s 
through the upcoming week. Dewpoints in the upper 60s will continue 
to result in very humid conditions. Apparent temperatures...ie heat 
indices...will be a couple of degrees higher than the actual air 
temperatures.

Nighttime lows in this stagnant pattern will fall to around 70 most 
nights. That said, the urban heat island effect will be in full 
force and city temperatures at night might not fall below the upper 
70s. 

After a brief respite, late in the week, the heat builds in again 
late next weekend. The GFS is showing h8 temps pushing 30c. That 
would send surface temps toward 100 a week from Monday. Impacts from 
the heat will start to ramp up as we go through next week and (if 
the GFS is correct) the week after.

-- Next decent chance of rain Friday --

Radar shows a lone shower has developed in Van Buren county. A 
couple more could develop in the next hour or so, but shouldn't 
amount to much.

Models are suggesting that a low will develop off the SE US coast 
and move northeast and help to briefly break down the blocky 
pattern. This allows a weak front to approach and produce showers 
and storms over the region. 

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 855 PM EDT Sat Jul 4 2020

VFR weather is expected for the most part the next 24 hours. The 
main chance of interrupting 24 hours of VFR weather from this
evening through Sunday evening will be the possibility of some
haze late tonight and Sunday morning. We have added 5 miles and
haze to the forecast at all sites from 09z to 13z. This is a
possibility given the fact that we are in a stagnant airmass and
we typically see a reduction in visibility in these regimes the
morning after the 4th (fireworks). Otherwise, expecting VFR to
prevail. We may see an isolated shower or thunderstorms affect MKG
and GRR Sunday afternoon after 20z. Too small of a threat to
include in the TAFs though. Winds will be under 10 knots through
Sunday evening.  

&&

.MARINE...
Issued at 320 PM EDT Sat Jul 4 2020

No marine hazards expected for the next several days. Waves will 
generally be a foot or less through Monday. 


&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...None.
&&

$$

SYNOPSIS...04
DISCUSSION...04
AVIATION...Duke
MARINE...04