Category: Typhoon Rule

Short-term Cold; Mid-range Warm…

There’s been a ton of conversation as of late about where this overall weather pattern is heading.  Perhaps it’s the Christmas season that brings out the conversation as everyone is hoping for that cold pattern to provide a White Christmas.

While in the short-term cold will continue to dominate, we’re becoming increasingly confident of an unseasonably mild stretch of air in the mid-range period.  That’ll take us up to the week before Christmas…

In the short-term, the positive PNA will continue to be the primary driver in our pattern.  This will ensure a colder east through the majority of week 1 (through next Friday).

pna.sprd2

A positive PNA pattern typically leads to below normal heights (trough) and associated cooler than normal pattern across the eastern region.

A positive PNA pattern typically leads to below normal heights (trough) and associated cooler than normal pattern across the eastern region.

Modeling sees the cool east in week 1 and warm west- typical of a positive PNA pattern:

gefs_t2anom_by5_conus_29

There are changes in the mid-range period that’ll have lovers of winter and cold frowning.  Many of our long-term readers know how we use the “typhoon rule” as a good indication of what we can expect across our region 6-10 days down the road.  As stated multiple times in the past (want to give credit where credit is due), we learned this from the great Joe Bastardi.  For those that are new here, I’ll describe this very briefly (you can read through the archives, if you’d like, for a longer/ more detailed description).  Typically when you have a recurving typhoon in the WPAC, that suggests a trough (colder pattern) across the central and eastern Lower 48.  On the flip side, when you have a westward moving typhoon, that’s a good indication of eastern ridging (warmer pattern).

Courtesy of the Joint Typhoon Warning Center, Super Typhoon Hagupit is forecast to move on a general westward trajectory.

wp2214

This is a very good sign of a much milder than normal period in the mid-range (days 8-12).  Modeling, in return, is going towards a warm pattern (associated ridge) week 2:

test8

The GFS ensembles and NAEFS agree on the warmth and given what we’ve discussed above, so do we:

2014120412_054@007_E1_north@america_I_NAEFS@TEMPERATURE_anomaly@probability@combined@week2_186

D12

In fact, it wouldn’t surprise us to see high temperatures in the 55-60 degree range during a day or two week 2.

Really quick and before we end- lovers of winter weather, there’s absolutely NO reason to throw in the towel.  In fact, indications in the long range suggest the trough collapses into the east during the week leading up to Christmas and that could provide for all sorts of wintry “mischief” when almost all of folks are wanting snow…

Much more on that in the days ahead.  Have a great night!

Permanent link to this article: https://indywx.com/2014/12/04/short-term-cold-mid-range-warm/

More On The “Typhoon Rule”

Perhaps you’ve heard folks discuss the “typhoon rule” over the past few weeks. What I despise is when people take credit for certain ideas without giving credit where credit is…

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Permanent link to this article: https://indywx.com/2014/09/22/more-on-the-typhoon-rule/

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