Frequency change for BWI Tower?

Aviation Notable Activity
1

I live in the BWI area and frequently listen to ATC radio for the tower, which has been 119.4.
Listening in today, aircraft are calling into that frequency and being told that the tower is now 123.75.

Anybody have any idea why this switch would occur or if this is a permanent thing?

2

I went to the FAA and looked up NOTAMS for BWI

NOTAM 10/026: Baltimore/Washington International Thurgood Marshal Airport (KBWI)

!BWI 10/026 BWI COM REMOTE TRANSMITTER RECEIVER 123.75 VICE 119.4
CREATED: 10 Oct 2012 10:05:00