Surprisingly, it warmed up to 4F for the first part of the
night and snowed, dropping 0.02” of precipitation. It then cleared out and briefly
dropped to -4F, and surprisingly, a south-southwesterly wind of 15 kt was
recorded. It cooled down quickly when the wind calmed down a bit and turned to
southerly. There is a big temperature difference between a southwesterly and a
south/southeasterly wind, perhaps due to the bright, white farmland to the east
and darker, warmer urban area to the west. Plenty of sunshine led to a rapid
warm up but still only up to 21F so far, still colder than modeled. Also note
all the local temperature variations! Winds have calmed down with the diurnal wind
cycle, which imposes an easterly wind during the day, counteracting the
synoptic-scale forcing for westerly winds.
Not a cloud in the sky expected for day 6. Tonight,
with clear skies and snow cover, some radiational cooling will occur, albeit
counteracted by warming temperatures just aloft. South/southwesterly winds will
also return, perhaps even a bit stronger than last night, with the diurnal wind
imposing a westerly wind, enhancing the synoptic-scale forcing. Sunny skies tomorrow
will lead to a rapid warmup, leading to the high being much warmer than today,
but winds will turn to southeasterly or become calm, once again not allowing downsloping
or urban effect warming. It will likely be colder than modeled again tonight
into tomorrow, with a persistence bias likely to work well, due to not much change
in the synoptic-scale pattern with ridging overhead, except for just a warming
air column.
No comments:
Post a Comment